Display panel and manufacturing method thereof

Abstract

Embodiments of the present invention disclose a display panel and a method for manufacturing the same. In one specific embodiment, the display panel includes multiple functional film layers disposed on a substrate and alignment test marks disposed in the same layer as at least some of the functional film layers, wherein the alignment test marks disposed in the same layer as the functional film layer of the fluid material are block-shaped. This embodiment can prevent edge loss or deformation of the alignment test marks disposed in the same layer as the functional film layer of the fluid material, effectively maintaining the morphology of the alignment test marks disposed in the same layer as the functional film layer of the fluid material, thereby ensuring the accuracy of the alignment test mark fit accuracy measurement, thereby ensuring the accuracy of the film layer alignment accuracy judgment of the display panel.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and more particularly to a display panel and a method for manufacturing the same. Background Art

[0002] For example, display panels such as Micro Organic Light-Emitting Diode (MicroOLED) have several or even dozens of film layers in their manufacturing process, which also includes numerous film patterns. Accurate alignment of the film patterns needs to be ensured between different functional film layers. Due to differences in film thickness and film pattern between different functional film layers, the alignment between the functional film layers cannot be directly measured after the functional film layers are covered. A commonly used solution is to form some alignment test marks (also called test element groups TEGs) in the edge area outside the display area of ​​the display panel, which are set on the same layer as the functional film layer, for measuring the alignment accuracy of the film layer. By measuring the overlay accuracy between the alignment test marks of the two functional film layers, it is determined whether the alignment error between the two functional film layers is within the specification, thereby determining the film process accuracy. The inventors have discovered that existing alignment test mark designs may have edge loss or deformation problems, especially for functional film layers of fluid materials such as color glue layers and photoresist layers. This problem is prone to occur in alignment test marks set on the same layer. Summary of the Invention

[0003] An object of the present invention is to provide a display panel and a method for manufacturing the same, so as to solve at least one of the problems existing in the prior art.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] A first aspect of the present invention provides a display panel, which includes multiple functional film layers arranged on a substrate and alignment test marks arranged on the same layer as at least part of the functional film layers, wherein the alignment test marks arranged on the same layer as the functional film layer of the fluid material are block-shaped.

[0006] Optionally, a first alignment test mark provided on the same layer as the first functional film layer and a second alignment test mark provided on the same layer as the second functional film layer for measuring the alignment accuracy between the first functional film layer and the second functional film layer constitute an alignment test mark group.

[0007] Optionally, in a plane parallel to the substrate, the shapes of the first alignment test marks of adjacent alignment test mark groups are different and / or the shapes of the second alignment test marks are different.

[0008] Optionally, when the first functional film layer and the second functional film layer are respectively functional film layers of fluid materials and the second functional film layer is farther away from the substrate than the first functional film layer, the orthographic projection of the first alignment test mark on the substrate covers the orthographic projection of the second alignment test mark on the substrate.

[0009] Optionally, a designed position of an orthographic projection center of the first alignment test mark on the substrate coincides with a designed position of an orthographic projection center of the second alignment test mark on the substrate.

[0010] Optionally, when one of the first functional film layer and the second functional film layer is a functional film layer made of non-fluid material, there is no overlapping area between the orthographic projection of the first alignment test mark on the substrate and the orthographic projection of the second alignment test mark on the substrate.

[0011] Optionally, the alignment test mark provided on the same layer as the functional film layer of the non-fluid material is in the shape of a block, a ring or a strip.

[0012] Optionally, the display panel further includes a film thickness test mark provided on the same layer as at least part of the functional film layer.

[0013] Optionally, the film thickness test mark includes a block-shaped film thickness test mark for measuring film thickness and a plurality of strip-shaped film thickness test marks arranged at intervals for positioning the block-shaped film thickness test mark.

[0014] Optionally, the display panel is a micro organic light emitting diode display panel or a micro light emitting diode display panel.

[0015] A second aspect of the present invention provides a method for manufacturing a display panel, which is applied to the display panel provided in the first aspect of the present invention, and the method comprises:

[0016] A plurality of functional film layers are formed on a substrate, wherein an alignment test mark is formed on the same layer as the functional film layer when at least a portion of the functional film layers are formed, and the alignment test mark is formed on the same layer as the functional film layer of the fluid material in a block shape.

[0017] The beneficial effects of the present invention are as follows:

[0018] The technical solution described in the present invention can avoid edge loss or deformation of the alignment test mark set on the same layer as the functional film layer of the fluid material, and effectively maintain the morphology of the alignment test mark set on the same layer as the functional film layer of the fluid material, so as to ensure the accuracy of the measurement of the alignment accuracy of the alignment test mark, thereby ensuring the accuracy of the judgment of the film layer alignment accuracy of the display panel. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0020] Figure 1 A schematic diagram showing an existing display panel.

[0021] Figure 2 A schematic diagram showing edge loss and deformation of an existing alignment test mark.

[0022] Figure 3 A schematic diagram showing a display panel provided by this embodiment is shown.

[0023] Figure 4 A schematic cross-sectional view of an alignment test mark 3209 and an alignment test mark 3210 is shown.

[0024] Figure 5 Another schematic diagram of the display panel provided by this embodiment is shown. DETAILED DESCRIPTION

[0025] The terms “on…”, “formed on…” and “disposed on…” used in the present invention may mean that one layer is directly formed or disposed on another layer, or may mean that one layer is indirectly formed or disposed on another layer, i.e., there are other layers between the two layers.

[0026] It should be noted that although the terms "first," "second," etc. may be used herein to describe various parts, components, elements, regions, layers, and / or portions, these parts, components, elements, regions, layers, and / or portions should not be limited by these terms. Rather, these terms are used to distinguish one part, component, element, region, layer, and / or portion from another. Thus, for example, the first part, first member, first element, first region, first layer, and / or first portion discussed below may be referred to as a second part, second member, second element, second region, second layer, and / or second portion without departing from the teachings of the present invention.

[0027] In the present invention, unless otherwise specified, the term "co-layer arrangement" refers to two layers, components, members, elements, or parts that can be formed by the same manufacturing process (e.g., patterning process, etc.), and the two layers, components, members, elements, or parts are formed from the same material. For example, co-layer arrangement of two or more functional layers means that these co-layered functional layers can be formed using the same material layer and the same manufacturing process, thereby simplifying the manufacturing process of the display substrate.

[0028] In the present invention, unless otherwise specified, the expression "patterning process" generally includes the steps of photoresist coating, exposure, development, etching, photoresist stripping, etc. The expression "one-time patterning process" means a process of forming patterned layers, components, members, etc. using one mask.

[0029] The inventors have found that the existing alignment test mark design may have the problem of edge loss or deformation, especially for functional film layers such as color glue layers, photoresist layers and other fluid materials, the alignment test marks set on the same layer are prone to this problem. Specifically, the alignment test mark design commonly used in current product processes is as follows: Figure 1 As shown, Figure 1 In the embodiment, the display panel 10 includes or is divided into a display area 11 and an edge area 12, wherein the display panel on the film layer structure includes a substrate, a plurality of functional film layers arranged on the substrate, and an alignment test mark arranged on the same layer as at least part of the functional film layers, and the alignment test mark is arranged in the edge area 12, for example, the alignment test mark 1201 arranged on the same layer as the functional film layer a formed on the substrate and the alignment test mark 1202 arranged on the same layer as the functional film layer b formed on the functional film layer a constitute an alignment test mark group a, and the alignment test mark 1203 arranged on the same layer as the functional film layer b and the alignment test mark 1204 arranged on the same layer as the functional film layer c formed on the functional film layer b constitute an alignment test mark group b, wherein the alignment test mark 1201, alignment test mark 1202, alignment test mark 1203 and alignment test mark 1204 in the edge area 12 are, for example, respectively formed on the substrate. It should be noted that, Figure 1 In the display panel 10 shown, the area of ​​the edge region 32 is enlarged to clearly illustrate the pattern design and arrangement of the alignment test mark. In actual products, the area of ​​the display region 31 is much larger, and the edge region 32 only occupies a smaller proportion of the area of ​​the display panel 10. Figure 1 As shown, each alignment test mark group adopts a ring-by-ring (Frame By Frame) pattern design, specifically two rectangular rings, and the alignment between the two film layer processes is determined by measuring the alignment test mark fitting accuracy, such as measuring the center deviation of the two alignment test marks in the alignment test mark group. For example, the alignment accuracy between the functional film layer a and the functional film layer b is determined by measuring the center deviation of the alignment test mark 1201 and the alignment test mark 1202 in the alignment test mark group a, and the alignment accuracy between the functional film layer b and the functional film layer c is determined by measuring the center deviation of the alignment test mark 1203 and the alignment test mark 1204 in the alignment test mark group b. This alignment test mark design is easier to maintain the morphology of the alignment test mark set on the same layer as the functional film layer of non-fluid materials such as the metal material layer of the cathode layer and the oxide material of the buffer layer, and the measurement accuracy is relatively high. However, for the functional film layer of fluid materials such as the color glue layer and the photoresist layer, in the glue process, such as the color glue process and the photoresist glue process, the morphology of the alignment test mark set on the same layer as the functional film layer of the fluid material often changes due to the fluidity of the glue, for example Figure 3As shown in the figure, assuming that the functional film layer b and the functional film layer c are functional film layers of fluid materials, the alignment test mark set on the same layer as the functional film layer b is likely to have an edge loss and become Figure 3 The shape of 1203 shown in FIG. 1203 may be deformed and become Figure 3 The morphology of 1203`` shown in the figure is likely to have edge loss and become the alignment test mark set on the same layer as the functional film layer c. Figure 3 The shape of 1204' shown in FIG. 1 may be deformed to become Figure 3 The morphology of 1204`` is shown. Obviously, if this happens, it will seriously affect the accuracy of the measurement.

[0030] In view of this, if Figure 3 As shown, one embodiment of the present invention provides a display panel, comprising a plurality of functional film layers arranged on a substrate and an alignment test mark arranged on the same layer as at least part of the functional film layers, wherein the alignment test mark arranged on the same layer as the functional film layer of the fluid material is block-shaped.

[0031] It can be understood that the block shape in this embodiment refers to a shape with equal or approximately equal length and width, which can be, for example, a roughly rectangular shape. The block shape can also be roughly circular, roughly elliptical, etc. Unlike the ring shape with an opening inside, the block shape has no opening inside.

[0032] The display panel provided in this embodiment avoids edge loss or deformation of the alignment test marks arranged on the same layer as the functional film layer of the fluid material, by designing the alignment test marks arranged on the same layer as the functional film layer of the fluid material, such as the color glue layer, the photoresist layer, etc., to be block-shaped and not easily deformed. This effectively maintains the morphology of the alignment test marks arranged on the same layer as the functional film layer of the fluid material, thereby ensuring the accuracy of the measurement of the alignment test mark fitting accuracy, and thus ensuring the accuracy of the film layer alignment accuracy judgment of the display panel.

[0033] For example Figure 3 As shown, the display panel 30 includes or is divided into a display area 31 and an edge area 32, wherein the display panel on the film layer structure includes a substrate, multiple functional film layers arranged on the substrate, and an alignment test mark arranged on the same layer as at least part of the functional film layers, and the alignment test mark is arranged in the edge area 32. Figure 3 As shown, the display panel 30 includes a substrate and functional film layers A, B, C, D, E, F, G, H, I, J and K stacked sequentially on the substrate, with a total of 10 functional film layers, among which the functional film layer E is a functional film layer of fluid material, and the alignment test mark 3208 and the alignment test mark 3209 arranged on the same layer as the functional film layer E are block-shaped.

[0034] In a possible implementation, a first alignment test mark provided on the same layer as the first functional film layer and a second alignment test mark provided on the same layer as the second functional film layer for measuring the alignment accuracy between the first functional film layer and the second functional film layer constitute an alignment test mark group.

[0035] For example Figure 3 As shown:

[0036] The alignment test mark 3201 provided on the same layer as the functional film layer A and the alignment test mark 3202 provided on the same layer as the functional film layer B constitute an alignment test mark group A. The alignment accuracy between the functional film layer A and the functional film layer B can be determined by measuring the center deviation between the alignment test mark 3201 and the alignment test mark 3202 in the alignment test mark group A.

[0037] The alignment test mark 3203 provided on the same layer as the functional film layer B and the alignment test mark 3204 provided on the same layer as the functional film layer C constitute an alignment test mark group B. The alignment accuracy between the functional film layer B and the functional film layer C can be determined by measuring the center deviation between the alignment test mark 3203 and the alignment test mark 3204 in the alignment test mark group B or the distance between the edge of the alignment test mark 3203 and the corresponding edge of the alignment test mark 3204.

[0038] The alignment test mark 3205 provided on the same layer as the functional film layer C and the alignment test mark 3206 provided on the same layer as the functional film layer D constitute an alignment test mark group C. The alignment accuracy between the functional film layer C and the functional film layer D can be determined by measuring the distance between the corresponding edges (inner and outer corresponding edges) of the alignment test mark 3205 and the alignment test mark 3206 in the alignment test mark group C.

[0039] The alignment test mark 3207 provided on the same layer as the functional film layer D and the alignment test mark 3208 provided on the same layer as the functional film layer E constitute an alignment test mark group D. The alignment accuracy between the functional film layer D and the functional film layer E can be determined by measuring the center deviation between the alignment test mark 3207 and the alignment test mark 3208 in the alignment test mark group D or the distance between the edge of the alignment test mark 3207 and the corresponding edge of the alignment test mark 3208.

[0040] The alignment test mark 3209 set on the same layer as the functional film layer E and the alignment test mark 3210 set on the same layer as the functional film layer F constitute the alignment test mark group E. The alignment accuracy between the functional film layer E and the functional film layer F can be judged by measuring the center deviation between the alignment test mark 3209 and the alignment test mark 3210 in the alignment test mark group E or the distance between the edge of the alignment test mark 3209 and the corresponding edge of the alignment test mark 3210.

[0041] Among them, the alignment test mark 3201, alignment test mark 3202, alignment test mark 3203, alignment test mark 3204, alignment test mark 3205, alignment test mark 3206, alignment test mark 3207, alignment test mark 3208, alignment test mark 3209 and alignment test mark 3210 in the edge area 12 are, for example, respectively formed on the substrate.

[0042] It should be noted that, in addition to the above-mentioned implementation method of using two alignment test marks to form an alignment test mark group, more alignment marks can also be used to form an alignment test mark group. For example, an alignment test mark set on the same layer as the functional film layer A, an alignment test mark set on the same layer as the functional film layer B, and an alignment test mark set on the same layer as the functional film layer C form a ring-ring-ring pattern to constitute an alignment test mark group, so that the alignment accuracy between the functional film layer A and the functional film layer B and the alignment accuracy between the functional film layer B and the functional film layer C can be judged by measuring the center deviation of the three alignment test marks in the alignment test mark group.

[0043] It should be noted that, in addition to Figure 3 While the alignment accuracy of each adjacent functional film layer (functional film layer A, functional film layer B, functional film layer C, functional film layer D, functional film layer E, and functional film layer F) needs to be determined, the alignment accuracy of certain adjacent functional film layers can also be selectively determined based on actual needs. Furthermore, the alignment accuracy of the functional film layers can be determined by separately determining the alignment accuracy of each of the functional film layers B, functional film layer C, functional film layer D, functional film layer E, and functional film layer F relative to functional film layer A.

[0044] It should be noted that, in addition to Figure 3 All the alignment test marks shown are rectangular. For example, alignment test mark 3208 and alignment test mark 3209 are divided into rectangular blocks. Other shapes such as circular, trapezoidal, L-shaped, or a combination of different shapes can also be used. However, it is necessary to try to ensure that the alignment test marks in the same alignment test mark group are similar in shape or a combination of shapes that are easy to measure, so as to facilitate the measurement of the alignment test mark fitting accuracy.

[0045] In a possible implementation, the alignment test mark provided on the same layer as a metal material layer such as a cathode layer or a functional film layer of a non-fluid material such as an oxide material of a buffer layer is in a block, ring or strip shape.

[0046] For example Figure 3As shown, the alignment test mark 3201 of the functional film layer A of the non-fluid material is annular, the alignment test mark 3202 of the functional film layer B of the non-fluid material is annular, and the alignment test mark 3203 is block-shaped, the alignment test mark 3204 of the functional film layer C of the non-fluid material is block-shaped, and the alignment test mark 3205 is strip-shaped, the alignment test mark 3206 of the functional film layer D of the non-fluid material is strip-shaped, and the alignment test mark 3207 is block-shaped, and the alignment test mark 3210 of the functional film layer F of the non-fluid material is block-shaped. Therefore: the test mark group A adopts a ring-by-ring (Frame By Frame) pattern design, which is suitable for the alignment between the functional film layer of non-fluid material and the functional film layer of non-fluid material; the test mark group B adopts a ring-block pattern design, which is suitable for the alignment between the functional film layer of non-fluid material and the functional film layer of fluid material, and also suitable for the alignment between the functional film layer of non-fluid material and the functional film layer of non-fluid material; the test mark group C adopts a bar-in-bar pattern design, which is also suitable for the alignment between the functional film layer of non-fluid material and the functional film layer of non-fluid material; the test mark group D adopts a bar-block pattern design, which is suitable for the alignment between the functional film layer of non-fluid material and the functional film layer of fluid material, and also suitable for the alignment between the functional film layer of non-fluid material and the functional film layer of non-fluid material; the test mark group E adopts a block-in-block (Block In The block-to-block pattern design adopted by the test mark group E is applicable to the alignment between functional film layers of fluid materials and functional film layers of fluid materials, and also applicable to the alignment between functional film layers of fluid materials and functional film layers of non-fluid materials, that is, the block-to-block pattern design adopted by the test mark group E is applicable to various situations.

[0047] Combine Figure 3 As shown, for the registration accuracy measurement, in one registration test mark group:

[0048] For example, if the first alignment test mark is a rectangular block or a rectangular ring, then: the second alignment test mark can be a rectangular ring, so that when performing the alignment accuracy measurement, the alignment distances of the four directions of upper, lower, left and right can be measured (in addition, the vertical deviation can be obtained by measuring one of the two directions of upper and lower, and the horizontal deviation can be obtained by measuring one of the two directions of left and right); the second alignment test mark can also be a rectangular block; the second alignment test mark can also be a strip, which only measures the horizontal or vertical deviation; the second alignment test mark can also be two strips parallel to the adjacent sides of the first alignment test mark in a plane parallel to the substrate, so as to respectively measure the deviation in the horizontal and vertical directions; the second alignment test mark can also be, for example Figure 3The alignment test mark 3207 shown has four parallel strips, a pair of which are parallel to each other and are respectively parallel to one of the adjacent sides of the first alignment test mark, and another pair of which are parallel to each other and are respectively parallel to the other adjacent side of the first alignment test mark, so as to measure the deviation in the horizontal and vertical directions respectively.

[0049] Similarly, for another example, if the first alignment test mark includes four bars forming a roughly rectangular shape, then the second alignment test mark can be a rectangular block, a rectangular ring, or four bars forming a roughly rectangular shape, all of which can achieve alignment accuracy measurement. For another example, if the first alignment test mark is a circular block, a circular ring, or includes multiple bars forming a roughly circular shape, then the second alignment test mark can be a circular block, a circular ring, or includes multiple bars forming a roughly circular shape. Similar procedures apply to other shapes, such as L-shaped, triangular, trapezoidal, and parallelogram shapes.

[0050] In a possible implementation, when the first functional film layer and the second functional film layer are both functional film layers of fluid materials and the second functional film layer is farther away from the substrate than the first functional film layer, the orthographic projection of the first alignment test mark on the substrate covers the orthographic projection of the second alignment test mark on the substrate. Figure 3 Test Marker Group E shown, see Figure 4 The alignment test mark 3210 set on the same layer as the functional film layer F is formed on the alignment test mark 3209 set on the same layer as the functional film layer E, and the orthographic projection of the alignment test mark 3209 on the substrate covers the orthographic projection of the alignment test mark 3210 on the substrate.

[0051] In a possible implementation, the designed position of the orthographic projection center of the first alignment test mark on the substrate coincides with the designed position of the orthographic projection center of the second alignment test mark on the substrate. Figure 3 and Figure 4 As shown, the designed position of the center of the orthographic projection of the alignment test mark 3209 on the substrate and the designed position of the center of the orthographic projection of the alignment test mark 3210 on the substrate are convenient for measuring the fitting accuracy.

[0052] In a possible implementation, when one of the first functional film layer and the second functional film layer is a functional film layer made of a non-fluid material, the orthographic projection of the first alignment test mark on the substrate and the orthographic projection of the second alignment test mark on the substrate do not have an overlapping area. Figure 3 The test mark group A, test mark group B, test mark group C and test mark group D shown in the figure facilitate the measurement of the fitting precision and help improve the accuracy of the measurement of the fitting precision.

[0053] In a possible implementation, in a plane parallel to the substrate, the shapes of the first alignment test marks of adjacent alignment test mark groups are different and / or the shapes of the second alignment test marks are different.

[0054] like Figure 1 As shown, the existing alignment test mark pattern is designed so that the alignment test mark groups have the same shape. In this way, it is easy to cause mismeasurement (machine misgrabbing) when measuring the fit accuracy. If the spacing between adjacent alignment test mark groups is increased, although the mismeasurement rate can be reduced, the occupied non-display area will increase, which is not conducive to improving the display area ratio, especially for small-sized products. The above implementation method, through Figure 3 The differentiated shape design of adjacent alignment test mark groups shown can reduce the measurement error rate through differentiated shapes that are easy for the machine to identify, without increasing the spacing between adjacent alignment test mark groups or even further reducing the spacing between adjacent alignment test mark groups, which is beneficial to the design of small-size products.

[0055] In a possible implementation, the display panel further includes a film thickness test mark provided on the same layer as at least part of the functional film layer.

[0056] In one possible implementation, Figure 5 As shown, the film thickness test mark includes a block film thickness test mark 3211 for measuring film thickness and a plurality of strip film thickness test marks 3212 arranged at intervals for positioning the block film thickness test mark 3211 . Among them, the block film thickness test mark 3211 adopts a whole block design, which is conducive to measuring the thickness of the functional film layer set in the same layer by measuring the thickness of the block film thickness test mark 3211. For example, when the film thickness test mark 3211 is set on the substrate, the thickness of the functional film layer set in the same layer can be measured by measuring the height difference between the top surface edge of the block film thickness test mark 3211 and the substrate. The pattern design of the multiple strip film thickness test marks 3212 is similar to a grating, which is conducive to machine positioning or grabbing the film thickness test marks and adjusting the clarity. For example, the machine can first locate the multiple strip film thickness test marks 3212 according to the preset coordinates, and then focus, and then locate the block film thickness test mark 3211 according to the multiple strip film thickness test marks 3212 and the block film thickness test mark 3211 in the film thickness test mark, and then measure the thickness.

[0057] In a possible implementation, the display panel provided in this embodiment may be a micro organic light-emitting diode (Micro Organic Light-Emitting Diode, MicroOLED) or a micro light-emitting diode (Mini Light Emitting Diode, Mini-LED).

[0058] Another embodiment of the present invention provides a display device comprising the display panel provided in the above embodiment. The display device can be any product or component with a display function, such as a mobile phone, tablet computer, television, monitor, laptop computer, digital photo frame, or navigation system, and this embodiment does not limit this.

[0059] Another embodiment of the present invention provides a method for manufacturing a display panel, which is applied to the display panel provided in the above embodiment. The method includes:

[0060] A plurality of functional film layers are formed on a substrate, wherein an alignment test mark is formed on the same layer as the functional film layer when at least a portion of the functional film layers are formed, and the alignment test mark is formed on the same layer as the functional film layer of the fluid material in a block shape.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in this field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A display panel, characterized in that: The display panel includes a plurality of functional film layers provided on a substrate and an alignment test mark provided on the same layer as at least part of the functional film layers, wherein the alignment test mark provided on the same layer as the functional film layer of the fluid material is block-shaped; A first alignment test mark provided on the same layer as the first functional film layer and a second alignment test mark provided on the same layer as the second functional film layer for measuring the alignment accuracy between the first functional film layer and the second functional film layer constitute an alignment test mark group; In a plane parallel to the substrate, the shapes of the first alignment test marks of adjacent alignment test mark groups are different and / or the shapes of the second alignment test marks are different.

2. The display panel according to claim 1, wherein: When the first functional film layer and the second functional film layer are respectively functional film layers of fluid materials and the second functional film layer is farther away from the substrate than the first functional film layer, the orthographic projection of the first alignment test mark on the substrate covers the orthographic projection of the second alignment test mark on the substrate.

3. The display panel according to claim 2, wherein: A designed position of an orthographic projection center of the first alignment test mark on the substrate coincides with a designed position of an orthographic projection center of the second alignment test mark on the substrate.

4. The display panel according to claim 1, wherein: When one of the first functional film layer and the second functional film layer is a functional film layer made of non-fluid material, the orthographic projection of the first alignment test mark on the substrate and the orthographic projection of the second alignment test mark on the substrate do not overlap.

5. The display panel according to any one of claims 1 to 4, characterized in that: The alignment test mark provided on the same layer as the functional film layer of the non-fluid material is in the shape of a block, a ring or a strip.

6. The display panel according to claim 1, wherein: The display panel further includes a film thickness test mark provided on the same layer as at least a portion of the functional film layer.

7. The display panel according to claim 6, wherein: The film thickness test mark includes a block-shaped film thickness test mark for measuring film thickness and a plurality of strip-shaped film thickness test marks arranged at intervals for positioning the block-shaped film thickness test mark.

8. The display panel according to claim 1, wherein: The display panel is a micro organic light emitting diode display panel or a micro light emitting diode display panel.

9. A method for preparing a display panel, characterized in that: Applied to the display panel according to any one of claims 1 to 8, the method comprises: A plurality of functional film layers are formed on a substrate, wherein an alignment test mark is formed on the same layer as the functional film layer when at least a portion of the functional film layers are formed, and the alignment test mark is formed on the same layer as the functional film layer of the fluid material in a block shape.

Images