A metal carrier separation from a master process for folding screen

Abstract

The application provides a metal carrier separation from a master process for a folding screen, and relates to the technical field of folding display screens. The process steps comprise: covering a connecting film layer on the surface of a master etched with half-etching lines; twice etching from the position corresponding to the half-etching lines on the other surface of the master, so that the two surfaces of the master are penetrated, and the etching is continuously performed until the penetration width is close to or equal to the width of the half-etching lines; and then, the covered film layer is removed, so that the metal carrier is naturally separated from the master. After the twice abdominal membrane, the adhesion characteristics of the connecting film layer are used to realize the twice etching penetration and the separation of the metal carrier from the master without direct separation. The metal carrier produced by the above process has high smoothness of the edge section, no burrs, the size precision can be controlled within 20 microns, and the yield is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of folding display screen, in particular to a process for separating a metal carrier from a master. BACKGROUND

[0002] With the maturation of organic light emitting diode (OLED) display technology, various terminal manufacturers have successively launched flexible folding, rolling display electronic products. Generally speaking, in a typical OLED module stack, in order to ensure the overall flatness of the module, the thinnest stainless steel plate is usually used as a metal carrier (also known as a "support layer" or "support film layer") adjacent to the bottom layer of the stack. This metal carrier, as an important device of the folding screen, directly affects the quality of the folding screen.

[0003] At present, when processing the above-mentioned metal carrier, the way to separate the metal carrier from the master is generally divided into two types: one is to etch a half-etching line (3) around the metal carrier (2) as shown in Figure 1 , and then break the metal carrier (2) from the half-etching line (3) to separate the metal carrier (2) from the master (1); the other is to etch a through groove (4) completely around the metal carrier (2) as shown in Figure 2 , and only leave a half-etching thickness of connecting bridge (5) at a few positions, and then separate the master around the metal carrier (2) by breaking the connecting bridge (5).

[0004] In the above-mentioned first processing method, since the half-etching line has a certain width, about half of the half-etching line remains around the metal carrier after breaking, and the width of this part of the half-etching line is calculated into the outer dimension of the metal carrier, resulting in a 50-80 μm or even higher error in the size of the metal carrier, and the broken surface at the half-etching line is not smooth, with serious burr residue; and in the above-mentioned second processing method, although the broken surface around the metal carrier is relatively smooth in most areas, there is still burr after breaking at the connecting bridge.

[0005] Therefore, in order to improve the product quality of the above-mentioned metal carrier, it is urgent to seek a new solution to the problem of separating the metal carrier from the master. SUMMARY

[0006] The present application aims to solve at least one of the above-mentioned problems in the prior art. To this end, one object of the present application is to provide a process for separating a metal carrier from a master for a folding screen, which can avoid burrs at the edges of the metal carrier, make the broken surface around the edges of the metal carrier smooth, and greatly improve the size accuracy.

[0007] The folding screen metal carrier separation from the master process of the present application, the master surface etched with half-line covered a layer of connecting film layer; then from the master the other side surface corresponding to the position of the half-line twice etching, so that the master both sides of the version through, and continue to etch to the through width close to or equal to the width of the half-line; finally, the film layer is removed, and the metal carrier is naturally separated from the master.

[0008] Further, the master both sides of the surface are etched with the half-line, and the positions of the half-line on both sides correspond to each other.

[0009] Further, the thickness of the master is H, and the etching depth of the half-line is h, so that 0.25H≤h≤0.35H.

[0010] Further, the etching depth of the half-line is one third of the thickness of the master.

[0011] Further, only one side surface of the master is etched with the half-line.

[0012] Further, the thickness of the master is H, and the etching depth of the half-line is h, so that 0.5H≤h≤0.75H.

[0013] Further, the etching depth of the half-line is two thirds of the thickness of the master.

[0014] Further, the width of the half-line is 80-160μm.

[0015] Further, the specific process steps include:

[0016] S100, film covering: covering the photoresist film layer on both sides of the master surface, and exposing and developing the pre-halfline position on both sides of the surface;

[0017] S200, etching: etching the half-line at the pre-halfline position on both sides of the master surface;

[0018] S300, twice film covering: covering a layer of connecting film layer on one side surface of the master;

[0019] S400, twice etching: further etching the half-line position on the other side surface of the master, so that the master both sides of the version through, and continue to etch to the through width close to or equal to the width of the half-line;

[0020] S500, film stripping: removing the connecting film layer and the photoresist film layer on the master surface, and the metal carrier is naturally separated from the master.

[0021] Further, the specific process steps include:

[0022] S100, film covering: covering photoresist film layers on both sides of the master, and exposing and developing the position of the pre-prepared half-etching line on one side of the master;

[0023] S200, etching: etching a half-etching line at the position of the pre-prepared half-etching line on one side of the master;

[0024] S300, secondary film covering: covering a connecting film layer on one side of the master;

[0025] S400, secondary exposure and development: exposing and developing the position corresponding to the half-etching line on the other side of the master;

[0026] S500, secondary etching: etching the position corresponding to the half-etching line on the other side of the master, so that the two sides of the master are through, and the etching is continued until the through width is close to or equal to the width of the half-etching line;

[0027] S600, film removal: removing the connecting film layer and the photoresist film layer on the surface of the master, so that the metal carrier naturally separates and falls off from the master.

[0028] Further, the connecting film layer and the photoresist film layer are made of the same material.

[0029] Further, the thickness of the connecting film layer is at least the same as the thickness of the photoresist film layer.

[0030] The beneficial effects of the present application are:

[0031] 1) After the master is etched through twice, the connecting film layer with the adhesion property provided by the secondary film covering makes the metal carrier remain not separated from the master, avoiding the risk that the metal carrier is separated from the master due to the etching line being through in the etching process;

[0032] 2) After etching through, the smoothness of the edge section of the metal carrier is high due to the flushing of the section by the etching liquid, and there is no burr;

[0033] 3) After removing the film layer on the surface of the product in the film removal process, the metal carrier is naturally separated from the master, without the need to break the connection between the metal carrier and the master by external force, avoiding the possible deformation of the product;

[0034] 4) The size precision of the metal carrier produced by the process of the present application can be controlled within 20 μm, and the yield is greatly improved;

[0035] In addition, other additional aspects and advantages of the present application will be partially given in the following description, partially will become obvious from the following description, or will be understood through the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 This is a schematic diagram of the existing technology for etching half-line engravings between a metal carrier and a master plate.

[0037] Figure 2 A schematic diagram of a structure in the prior art that reserves a connecting bridge between a metal carrier and a mother plate;

[0038] Figure 3 This is a schematic diagram of one embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of a half-etched line structure in the present invention;

[0040] Figure 5 This is a schematic diagram of another embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of another half-etched line structure in the present invention;

[0042] In the diagram: 1. Master plate; 2. Metal carrier; 3. Half-etched line; 31. Front half-etched line; 32. Back half-etched line; 4. Through groove; 5. Connecting bridge; 6. Photoresist film layer; 7. Connecting film layer. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0044] See attached document Figures 3 to 6 As shown, the present invention provides a process for detaching a metal carrier for a foldable screen from a master plate. In this process, a connecting film layer 7 is covered on the surface of a master plate 1 with etched half-line 3. A second etching is performed on the other side of the master plate 1 at the position corresponding to the half-line 3, so that the two sides of the master plate 1 are connected. The etching continues until the width of the connection is close to or equal to the width of the half-line 3. After removing the covering film layer, the metal carrier 2 naturally separates and falls off from the master plate 1.

[0045] One specific embodiment of the present invention comprises the following steps:

[0046] Step 1: Lamination

[0047] like Figure 3 As shown in (a), after cleaning, the master plate 1 is coated with a layer of photoresist on both sides of the master plate 1. After drying, the photoresist forms a uniform photoresist film layer 6. Then, the position of the pre-made half-etched line 3 on one side of the master plate 1 is exposed and developed, as shown in (a).Figure 3 As shown in (b), a pattern corresponding to the pre-made half-etched line 3 is formed on the photoresist film layer 6 on this side.

[0048] It should be noted that the position of the pre-made half-line 3 mentioned above refers to the position outside the edge of each metal carrier 2 on the master plate 1, and this position surrounds the edge of the metal carrier 2.

[0049] Step 2, Etching:

[0050] Place the coated master plate 1 from the previous step into the etching equipment, such as... Figure 3 As shown in (c), a half-line 3 is etched at the position of the pre-made half-line 3 on one side surface of the master plate 1, that is... Figure 4 The front half-scale line 31.

[0051] The width of the semi-etched line 3 is preferably 80–160 μm, such as 80 μm, 100 μm, 120 μm, or 160 μm. It should be noted that, generally, the etching width of the semi-etched line 3 should be between 120 and 160 μm. This is because the original processing method required breaking the reserved thickness at the semi-etched line 3 using external force. If the width of the semi-etched line 3 is small, the metal carrier 2 is easily damaged during the breaking process, affecting its accuracy. However, in this solution, since the metal carrier 2 is subsequently separated from the master plate 1 through secondary etching, the width of the semi-etched line 3 can be selected within a range less than 120 μm.

[0052] like Figure 4 As shown, the thickness of the master plate 1 is H, and the etching depth of the half-etched line 3 is h. H and h preferably satisfy: 0.5H ≤ h ≤ 0.75H. For example, if the thickness of the master plate 1 is 100 μm, the etching depth of the half-etched line 3 can be 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, or 75 μm, etc. In this way, the remaining thickness after etching ensures a continued effective connection between the metal carrier 2 and the master plate 1, while preventing the opening of the half-etched line 3 from shrinking due to the weight of the metal carrier 2 and the master plate 1. It also facilitates rapid penetration of the master plate 1 during the subsequent secondary etching, allowing the etching solution sufficient time to wash the cross-section of the metal carrier 2 edge, resulting in a smoother cross-section. More preferably, the etching depth of the half-etched line 3 should be two-thirds of the thickness of the master plate 1, which has been verified to provide the best overall effect.

[0053] Step 3, Secondary lamination:

[0054] like Figure 3(d) shows that the side surface of the master 1 with the half-etching line 3 is covered with a connecting film layer 7, which is a photoresist film layer coated by the same method as in step one. It is worth mentioning that in some cases, the connecting film layer 7 can also be made of a material different from the photoresist film layer 6.

[0055] The connecting film layer 7 connects the metal carrier 2 and the master 1 at the opening of the half-etching line 3. In order to ensure that the connecting film layer 7 has sufficient strength so that it can form an effective connection between the metal carrier 2 and the master 1 after the half-etching line 3 is etched through, the thickness of the connecting film layer 7 is at least the same as the thickness of the photoresist film layer 6, that is, the thickness of the connecting film layer 7 ≥ the thickness of the photoresist film layer 6, for example, the connecting film layer 7 has 1 times or 1.5 times the thickness of the photoresist film layer 6.

[0056] Step four, secondary exposure and development:

[0057] Taking the above-mentioned master 1 with the secondary film, the other side surface of the master 1 corresponding to the position of the half-etching line 3 is exposed and developed, and the other side surface is the side surface that has not been coated with the secondary film.

[0058] As Figure 3 (d) shows that the photoresist film layer 6 on this side is formed with a pattern corresponding to the half-etching line 3 on the other side after secondary exposure and development.

[0059] Step five, secondary etching:

[0060] As Figure 3 (e) shows that the master 1 is etched at the position corresponding to the half-etching line 3 on the other side surface of the master 1 that has not been coated with the secondary film, so that the two sides of the master 1 are through, and the etching continues until the through width is close to or equal to the width of the half-etching line 3. During this process, the edge of the metal carrier 2 is washed by the etching solution, making the cross section of the edge of the metal carrier 2 smooth and without burrs; and due to the presence of the connecting film layer 7, the metal carrier 2 continues to be connected to the master 1 after secondary etching.

[0061] Step six, film removal:

[0062] After secondary etching, the metal carrier 2 and the master 1 are essentially separated, and they are connected only by the connecting film layer 7. Then, as Figure 3 (f) shows that the connecting film layer 7 and the photoresist film layer 6 on the surface of the master 1 are removed, and then the metal carrier 2 naturally separates and falls off from the master 1.

[0063] After cleaning, the metal carrier 2 product with smooth edge section and no burr can be obtained, the size accuracy can reach within 20 μm, and the yield is also greatly improved compared with the original processing method. In addition, since the burr and size deviation do not need to be repaired again, the production efficiency is improved to a certain extent.

[0064] It is worth noting that in the above secondary coating step, a connecting film layer 7 can be coated on both sides of the master 1 without considering the control cost, and then the connecting film layer 7 at the subsequent secondary etching position is removed by exposure and development.

[0065] Another specific embodiment of the application is as follows:

[0066] Step one, coating:

[0067] As shown in (a), the cleaned master 1 is coated with a photoresist film layer 6 on both sides of the master 1, and the positions of the pre-prepared half-etching lines 3 on both sides are exposed and developed, as shown in (b). Figure 5 (b), patterns corresponding to the pre-prepared half-etching lines 3 are formed on both sides of the photoresist film layer 6. Figure 5 Step two, etching:

[0068] The master 1 coated in the previous step is placed in an etching device, as shown in (c).

[0069] (c), the pre-prepared half-etching lines 3 on both sides of the master 1 are etched to form half-etching lines 3, that is, front half-etching lines 31 and back half-etching lines 32 in (d).The width of the half-etching line 3 is 80-160 μm, for example, 80 μm, 100 μm, 120 μm or 160 μm, etc. Figure 5 Figure 6 As shown in (d), the thickness of the master 1 is H, and the etching depth of the half-etching line 3 is h, and H and h preferably satisfy: 0.25H≤h≤0.35H. For example, the thickness of the master 1 is 100 μm, and the etching depth of the half-etching line 3 can be 25 μm, 30 μm or 35 μm, etc.

[0070] As shown in (d), the thickness of the master 1 is H, and the etching depth of the half-etching line 3 is h, and H and h preferably satisfy: 0.25H≤h≤0.35H. For example, the thickness of the master 1 is 100 μm, and the etching depth of the half-etching line 3 can be 25 μm, 30 μm or 35 μm, etc. Figure 6 It is worth noting that the above steps in this embodiment are basically the same as the effect obtained in step two of the previous embodiment, and the advantage is that the double-sided half-etching method is used in this embodiment to avoid the case that the etching line is too deep in single-sided processing, and the opening of the half-etching line 3 is further improved due to the sinking of the metal carrier 2 and the master 1 due to self-weight. In addition, subsequent repeated operations such as secondary exposure and development are not required, and the production efficiency is improved.

[0071] Step three, secondary coating:

[0072]

[0073] ​like Figure 5 As shown in (d), a connecting film layer 7 is covered on one side surface of the master plate 1.

[0074] It should be noted that the connecting film layer 7 in this embodiment is basically the same as that in the previous embodiment. The difference is that the connecting film layer 7 with secondary lamination in this embodiment can be covered on either side of the master plate 1.

[0075] Step 4, Secondary Etching:

[0076] like Figure 5 As shown in (e), the half-etched line 3 is further etched on the other side of the master plate 1 that has not undergone secondary lamination, so that the two sides of the master plate 1 are connected, and etching continues until the width of the connection is close to or equal to the width of the half-etched line 3. During this process, the metal carrier 2 is also smoothed and burr-free by rinsing the cross-section of its edge with etching solution, and due to the presence of the connecting film layer 7, the metal carrier 2 remains connected to the master plate 1 after the secondary etching.

[0077] Step 5: Remove the film:

[0078] Then, as Figure 5 As shown in (f), after removing the connecting film layer 7 and the photoresist film layer 6 from the surface of the master plate 1, the metal carrier 2 will naturally separate and detach from the master plate 1. After subsequent cleaning, the metal carrier 2 product can be obtained.

[0079] It should be noted here that, for the other embodiment described above, since some additional descriptions and advantages are the same as those in the previous embodiment, in order to avoid repetition, some contents in the later embodiments may be omitted, but this should not be considered as the relevant contents not being included or disclosed in the later embodiments.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention and not to limit them. Although the embodiments of the present invention have been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the embodiments of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A process for folding screen metal carrier off master, characterized by the steps of The application comprises the following steps: covering photoresist film layer (6) on both sides of the master plate (1), and exposing and developing the position of the pre-prepared half-line (3) on one side or both sides of the master plate (1) to form the pattern corresponding to the pre-prepared half-line (3) on the photoresist film layer (6) of the surface; etching the position of the pre-prepared half-line (3) on one side or both sides of the master plate (1) to form the half-line (3); covering the surface of the master plate (1) on which the half-line (3) is etched with a connecting film layer (7); further etching the position corresponding to the half-line (3) on the other surface of the master plate (1) which is not covered with the connecting film layer (7) to make the two surfaces of the master plate (1) through, and continue etching until the through width is close to or equal to the width of the half-line (3); removing the connecting film layer (7) and the photoresist film layer (6) on the surface of the master plate (1) to make the metal carrier (2) naturally separate and fall off from the master plate (1); wherein when the exposure, development and etching to form the half-line (3) in the above steps are only carried out on one side of the master plate (1), the position corresponding to the half-line (3) on the other surface of the master plate (1) which is not covered with the connecting film layer (7) must be exposed and developed before the further etching to form the pattern corresponding to the pre-prepared half-line (3) on the photoresist film layer (6) of the other surface.

2. The process for folding screen metal carrier off master according to claim 1, characterized in that, The half-line (3) is etched on both surfaces of the master plate (1), and the positions of the half-lines (3) on both sides correspond to each other.

3. The process for folding screen metal carrier off master according to claim 2, characterized in that, The thickness of the master plate (1) is H, and the etching depth of the half-line (3) is h, so that 0.25H≤h≤0.35H.

4. The process for folding screen metal carrier off master according to claim 2, characterized in that, The etching depth of the half-line (3) is one third of the thickness of the master plate (1).

5. The process for folding screen metal carrier off master according to claim 1, wherein, Only one side of the master plate (1) is etched with the half-line (3).

6. The process for folding screen metal carrier off master according to claim 5, characterized in that, The thickness of the master plate (1) is H, and the etching depth of the half-line (3) is h, so that 0.5H≤h≤0.75H.

7. The process for folding screen metal carrier off master according to claim 5, wherein, The etching depth of the half-line (3) is two thirds of the thickness of the master plate (1).

8. The process for folding screen metal carrier off master according to claim 1, wherein, The width of the half-line (3) is 80-160μm.

9. The process for folding screen metal carrier off master according to claim 1, wherein, The connecting film layer (7) and the photoresist film layer (6) are made of the same material.

10. The process for folding screen metal carrier off master according to claim 1, wherein, The thickness of the connecting film layer (7) is at least the same as that of the photoresist film layer (6).

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