Mini LED board window opening and trimming method and mini LED board preparation method

Abstract

The present application provides a mini LED board window trimming method and a mini LED board preparation method. The above-mentioned mini LED board window trimming method includes: pre-processing the circuit board to remove the surface oxide of the circuit board; printing the solder resist ink on the surface of the circuit board through a silk screen to form a solder resist layer on the circuit board; baking the circuit board to solidify the solder resist layer; exposing the circuit board; developing the circuit board to form a first window; stacking a light shielding cover on the circuit board, the light shielding cover is formed with a light-transmitting hole, the light-transmitting hole coincides with the PAD window, and there is an excess solder resist ink layer between the first window and the PAD window; laser ablation of the excess solder resist ink layer in the light-transmitting hole to remove the excess solder resist ink layer in the light-transmitting hole. Since the laser ablates all the ink in the PAD window through the PAD window, all the ink in the PAD window is cleared, thereby improving the quality of the PAD window of the circuit board.

Description

Technical Field

[0001] The present invention relates to the technical field of mini LED board preparation methods, and in particular to a mini LED board window opening and trimming method and a mini LED board preparation method. Background Art

[0002] During the production process of circuit boards, solder resist ink, commonly known as green oil, needs to be printed on the board surface to protect the circuit. After the solder resist ink is printed, the solder resist ink in the area corresponding to the pad needs to be removed by exposure and development to expose the welding area of ​​the circuit, that is, to open a PAD window so that the circuit can be welded to the outside.

[0003] For mini LED boards, due to their design characteristics, it is necessary to open a smaller PAD window on the mini LED board. When the solder mask ink is printed thicker, in the process of the light source ultraviolet light being transmitted from the surface layer of the ink to the underlying ink, the ink's absorption of ultraviolet light will cause the energy of the ultraviolet light to gradually weaken, making the photocuring degree of the underlying ink weaker than that of the surface ink; since the PAD window belongs to the unexposed area, when the PAD window is corroded by the developing solution, the solution will corrode the underlying ink of the non-PAD window, causing the ink of the non-PAD window to float or even lose oil.

[0004] In order to avoid the problem of floating or even oil falling of the ink on the non-PAD window, the traditional technology ensures the complete solidification of the bottom ink on the non-PAD window by increasing the exposure energy. However, due to the high exposure energy, the light will be more easily refracted to the ink corresponding to the edge of the PAD window, so that the ink corresponding to the edge of the PAD window is solidified, which in turn makes the PAD window incomplete after development, resulting in poor quality of the PAD window. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a mini LED board window opening and trimming method and a mini LED board preparation method, which can make the PAD window oil-shedding complete and thus improve the quality of the PAD window.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] A mini LED panel window opening and trimming method, comprising:

[0008] Pre-treating the circuit board to remove surface oxides of the circuit board;

[0009] Printing solder resist ink on the surface of the circuit board through a silk screen to form a solder resist layer on the circuit board;

[0010] Performing a baking operation on the circuit board to solidify the solder resist layer;

[0011] Performing exposure processing on the circuit board;

[0012] Performing a developing process on the circuit board to form a first window;

[0013] Stacking a light shielding cover plate on the circuit board, wherein the light shielding cover plate is formed with a light transmission hole, the light transmission hole coincides with the PAD window, and there is a redundant solder resist layer between the first window and the PAD window;

[0014] Laser ablation is performed on the redundant solder resist layer in the light-transmitting hole to remove the redundant solder resist layer in the light-transmitting hole.

[0015] In one embodiment, in the step of printing the solder resist ink on the surface of the circuit board through the screen to form a solder resist layer on the circuit board, the scraper printing speed is set to 2m / min to 3m / min, the scraper thickness is 20mm, and the scraper pressure is 4kg / cm 2 Up to 6kg / cm 2 The scraper hardness is 70A to 75A, the scraper angle is 60 degrees to 80 degrees, and the distance between the screen and the circuit board surface is 2mm to 8mm.

[0016] In one embodiment, performing exposure processing on the circuit board includes:

[0017] Measure 9 points of the exposure table surface with a UV energy machine;

[0018] If the exposure amounts of the nine points are the same, the circuit board is exposed;

[0019] If the exposure amounts of any two points are different, the exposure machine should be adjusted.

[0020] In one of the embodiments, among the 9 points of the exposure surface measured by the UV energy machine, 9 points of the exposure surface are randomly selected for measurement.

[0021] In one of the embodiments, in the step of exposing the circuit board, the exposure energy is 8 full grids and the exposure delay is more than 10 seconds.

[0022] In one embodiment, in the step of baking the circuit board, the baking temperature is 68° C. to 75° C., and the baking time is 16 min to 20 min.

[0023] In one embodiment, in the step of developing the circuit board to form the first window, the developing pressure is 0.81.2 kg / cm2 Up to 1.2kg / cm 2 .

[0024] In one embodiment, the light-blocking cover includes a main board body and a reflective layer, wherein the reflective layer is coated and connected to the upper surface of the main board body, the main board body is formed with a through hole, and the reflective layer is also coated and connected to the inner wall of the through hole so that the reflective layer forms the light-transmitting hole in the through hole.

[0025] In one of the embodiments, the light shielding cover is formed with two alignment holes arranged at intervals, and the two alignment holes are connected to two positioning holes on the circuit board in a one-to-one correspondence.

[0026] A method for preparing a mini LED board, comprising the mini LED board window opening and trimming method described in any of the above embodiments.

[0027] Compared with the prior art, the present invention has at least the following advantages:

[0028] In the above-mentioned mini LED board window trimming method, when the light-shielding cover is stacked on the circuit board, the light-transmitting hole overlaps with the PAD window, so that the excess solder resist layer is still exposed after the light-shielding cover is stacked, so as to remove the excess solder resist layer. Since the laser burns away the excess solder resist layer in the light-transmitting hole through the light-shielding cover, that is, the laser burns away all the solder resist ink in the PAD window through the PAD window, so that all the solder resist ink in the PAD window is removed, thereby improving the quality of the PAD window of the circuit board. In addition, the light-shielding cover blocks the solder resist ink around the PAD window, avoiding accidental burning of the solder resist ink outside the PAD window during laser ablation, and ensuring that the protective effect of the solder resist ink on the circuit is not affected during laser ablation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 This is a flow chart of the steps of a mini LED panel window opening and trimming method according to an embodiment. DETAILED DESCRIPTION

[0031] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0032] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0034] The present application provides a mini LED board window opening and trimming method, including: pre-processing a circuit board to remove surface oxides of the circuit board; printing solder resist ink on the surface of the circuit board through a silk screen to form a solder resist layer on the circuit board; baking the circuit board to solidify the solder resist layer; exposing the circuit board; developing the circuit board to form a first window; stacking a light-shielding cover plate on the circuit board, the light-shielding cover plate forming a light-transmitting hole, the light-transmitting hole coinciding with the PAD window, and having an excess solder resist ink layer between the first window and the PAD window; laser ablating the excess solder resist ink layer in the light-transmitting hole to remove the excess solder resist ink layer in the light-transmitting hole.

[0035] In the above-mentioned mini LED board window trimming method, when the light-shielding cover is stacked on the circuit board, the light-transmitting hole overlaps with the PAD window, so that the excess solder resist layer is still exposed after the light-shielding cover is stacked, so as to remove the excess solder resist layer. Since the laser burns away the excess solder resist layer in the light-transmitting hole through the light-shielding cover, that is, the laser burns away all the solder resist ink in the PAD window through the PAD window, so that all the solder resist ink in the PAD window is removed, thereby improving the quality of the PAD window of the circuit board. In addition, the light-shielding cover blocks the solder resist ink around the PAD window, avoiding accidental burning of the solder resist ink outside the PAD window during laser ablation, and ensuring that the protective effect of the solder resist ink on the circuit is not affected during laser ablation.

[0036] like Figure 1 To better understand the technical solution and beneficial effects of the present application, the present application is further described in detail below in conjunction with specific embodiments:

[0037] A method for opening and trimming a mini LED panel window according to an embodiment of the present invention comprises:

[0038] S101: Pre-treating the circuit board to remove surface oxides of the circuit board.

[0039] In this embodiment, volcanic ash is used to remove oxides on the surface of the circuit board to increase the roughness of the board surface and enhance the adhesion of the board surface to the solder resist ink. After the circuit board is treated with volcanic ash, it is washed and dried again to make a clean and dry circuit board ready for screen printing of solder resist ink.

[0040] S103: Printing solder resist ink on the surface of the circuit board through a silk screen to form a solder resist layer on the circuit board.

[0041] In this embodiment, dense mesh holes are formed on the silk screen, the silk screen and the circuit board are stacked, and then the solder resist ink is scraped onto the silk screen by a scraper. The solder resist ink will adhere to the surface of the circuit board along the mesh holes, thereby forming a solder resist layer on the surface of the circuit board.

[0042] S105: The circuit board is baked to solidify the solder resist layer.

[0043] In this embodiment, since the solder resist ink still has fluidity after being screen printed on the circuit board, the circuit board needs to be baked to remove the solvent in the solder resist ink, thereby solidifying the solder resist ink on the circuit board.

[0044] S107: Expose the circuit board.

[0045] In this embodiment, the circuit board is exposed by an exposure machine so that the parts where the solder resist layer does not need to be removed are exposed, while the parts where the solder resist layer needs to be removed do not need to be exposed.

[0046] S109: developing the circuit board to form a first window.

[0047] In this embodiment, the exposed solder resist layer is solidified due to polymerization reaction. When the circuit board is developed, the exposed solder resist layer is still retained on the circuit board, that is, the exposed solder resist ink is still retained on the circuit board. The unexposed solder resist layer is washed away by the developing liquid, that is, the exposed solder resist ink is washed away by the developing liquid, so that a first window is formed on the circuit board, the first window is located in the PAD window, and the metal conductive layer of the circuit board is exposed in the first window.

[0048] S111: stacking a light shielding cover plate on the circuit board, wherein the light shielding cover plate is formed with a light transmission hole, the light transmission hole coincides with the PAD window, and there is a redundant solder resist layer between the first window and the PAD window.

[0049] In this embodiment, the light shielding cover has a light-proof property, and the light shielding cover can isolate the shielded part of the circuit board from the external laser. The light shielding cover is formed with a light-transmitting hole. When the light shielding cover is stacked on the circuit board, the light-transmitting hole overlaps with the PAD window, so that the metal conductive layer and the excess solder mask layer are exposed in the light-transmitting hole.

[0050] S113: performing laser ablation on the excess solder resist layer in the light-transmitting hole to remove the excess solder resist layer in the light-transmitting hole.

[0051] In this embodiment, the laser is aimed at the excess solder resist layer, i.e., the excess solder resist ink, in the light-transmitting hole, so that the laser ablates the excess solder resist layer, i.e., the excess solder resist ink, in the light-transmitting hole, thereby completely separating the solder resist layer in the PAD window from the circuit board. In one embodiment, the laser ablation operation is performed along the periphery of the light-transmitting hole, so that the laser ablates the excess solder resist layer, i.e., the excess solder resist ink, in the light-transmitting hole.

[0052] In the above-mentioned mini LED board window trimming method, when the light-shielding cover is stacked on the circuit board, the light-transmitting hole overlaps with the PAD window, so that the excess solder resist layer is still exposed after the light-shielding cover is stacked, so as to remove the excess solder resist layer. Since the laser burns away the excess solder resist layer in the light-transmitting hole through the light-shielding cover, that is, the laser burns away all the solder resist ink in the PAD window through the PAD window, so that all the solder resist ink in the PAD window is removed, thereby improving the quality of the PAD window of the circuit board. In addition, the light-shielding cover blocks the solder resist ink around the PAD window, avoiding accidental burning of the solder resist ink outside the PAD window during laser ablation, and ensuring that the protective effect of the solder resist ink on the circuit is not affected during laser ablation.

[0053] In one embodiment, in the step of printing solder resist ink on the surface of the circuit board through the screen to form a solder resist layer on the circuit board, the scraper printing speed is set to 2m / min to 3m / min, the scraper thickness is 20mm, and the scraper pressure is 4kg / cm 2 Up to 6kg / cm 2 , the scraper hardness is 70A to 75A, the scraper angle is 60 degrees to 80 degrees, and the distance between the screen and the circuit board surface is 2mm to 8mm.

[0054] In one embodiment, the exposure process of the circuit board includes: measuring 9 points of the exposure table by a UV energy machine; if the exposure amounts of the 9 points are the same, the circuit board is exposed; if the exposure amounts of any two points are different, the exposure machine is adjusted. In this embodiment, when the exposure amounts of the 9 points are the same, it indicates that the exposure of the exposure machine is uniform and can be used to expose the circuit board.

[0055] In one embodiment, among the 9 points on the exposure surface measured by the UV energy machine, 9 points on the exposure surface are randomly selected for measurement.

[0056] In one embodiment, in the step of exposing the circuit board, the exposure energy is 8 full grids and the exposure delay is more than 10 seconds, so that the exposure energy is high enough to solidify the bottom ink on the non-PAD window.

[0057] In one embodiment, in the step of baking the circuit board, the baking temperature is 68° C. to 75° C. and the baking time is 16 min to 20 min, so that the solvent in the solder resist ink layer is completely evaporated, thereby hardening the solder resist ink layer.

[0058] In one embodiment, in the step of developing the circuit board to form the first window, the developing pressure is 0.81.2 kg / cm 2 Up to 1.2kg / cm 2 , so that the ink in the first window is eaten away by the developer.

[0059] In one of the embodiments, the light-shielding cover includes a main board body and a reflective layer, the reflective layer is coated and connected to the upper surface of the main board body, the main board body is formed with a through hole, and the reflective layer is also coated and connected to the inner wall of the through hole, so that the reflective layer forms a light-transmitting hole in the through hole. In this embodiment, the main board body is placed on the circuit board so that the lower surface of the main board body is in contact with the circuit board. When the laser passes through the light-transmitting hole to ablate the excess solder resist ink layer in the light-transmitting hole, the laser will be reflected from the excess solder resist ink layer to the reflective layer in the light-transmitting hole, and then the laser will be reflected by the reflective layer in the light-transmitting hole, thereby avoiding the laser passing through the light-shielding cover to ablate the solder resist ink outside the PAD window, thereby ensuring the accuracy of ablation. Moreover, part of the laser reflected by the reflective layer in the light-transmitting hole is reflected into the solder resist ink layer, reducing the waste of laser energy and improving the efficiency of laser ablation. When the laser is accidentally irradiated toward the upper surface of the main board, the reflective layer will reflect the laser to the outside of the light-blocking cover due to the reflective layer covering and connected to the upper surface of the main board, thereby preventing the laser from passing through the light-blocking cover, thereby preventing the laser from accidentally ablating the solder mask ink outside the PAD window.

[0060] In one of the embodiments, the light shielding cover is formed with two alignment holes arranged at intervals, and the two alignment holes are connected to two of the positioning holes on the circuit board in a one-to-one correspondence. In this embodiment, a plurality of positioning holes are formed on the circuit board, and the plurality of positioning holes are arranged along the periphery of the circuit board, and each positioning hole is used to position the circuit board. In the step of stacking the light shielding cover on the circuit board, the light shielding cover is formed with a light-transmitting hole, the light-transmitting hole coincides with the PAD window, and there is an excess solder resist ink layer between the first window and the PAD window, the two alignment holes are connected to two of the positioning holes on the circuit board in a one-to-one correspondence, so that the light-transmitting hole coincides with the PAD window, thereby ensuring that the laser ablates the excess solder resist ink layer in the PAD window.

[0061] It can be understood that since the surface of the solder mask ink layer is a smooth surface, when the laser irradiates the ink in the PAD window, most of the laser will be reflected to the outside through the ink, making the efficiency of laser ablation of the ink in the PAD window low.

[0062] In order to improve the efficiency of laser ablation, in one embodiment, the size of the light-transmitting hole gradually increases from top to bottom, and the lower edge of the light-transmitting hole coincides with the edge of the PAD window. In this embodiment, when the light-shielding cover is stacked on the circuit board, since the size of the light-transmitting hole gradually increases from top to bottom, the hole wall of the light-transmitting hole is set toward the circuit board. In this way, when the laser is reflected to the hole wall of the light-transmitting hole, the hole wall of the light-transmitting hole will more easily reflect the laser back to the surface of the circuit board, reducing the waste of laser energy and improving the efficiency of laser ablation.

[0063] Furthermore, in the step of laser ablating the excess solder resist layer in the light-transmitting hole to remove the excess solder resist layer in the light-transmitting hole, the laser beam is inclined to the surface of the circuit board, and ablates along the lower edge of the light-transmitting hole so that the laser acts on the excess solder resist ink corresponding to the edge of the PAD window. In the present embodiment, the excess solder resist ink is located at the edge of the PAD window. Since the size of the light-transmitting hole gradually increases from top to bottom, the laser beam perpendicular to the board surface will not be able to directly act on the solder resist ink corresponding to the edge of the PAD window. Therefore, the laser beam is tilted to the surface of the circuit board so that the laser beam can directly act on the solder resist ink corresponding to the edge of the PAD window, thereby ensuring that the laser can completely ablate and remove the excess solder resist ink in the PAD window, that is, ensuring that the PAD window is completely de-oiled, thereby improving the quality of the PAD window.

[0064] In one of the embodiments, in the step of laser ablation of the excess solder mask in the light-transmitting hole to remove the excess solder mask in the light-transmitting hole, the smoke in the light-transmitting hole is simultaneously extracted. In this embodiment, while the excess solder mask is laser ablated, the smoke in the light-transmitting hole is extracted by an exhaust fan to prevent the smoke formed by laser ablation from polluting the working environment.

[0065] In order to further improve the efficiency of laser ablation, in one embodiment, after the step of developing the circuit board to form a first window, and before the step of stacking a light shielding cover on the circuit board, the light shielding cover is formed with a light-transmitting hole, the light-transmitting hole coincides with the PAD window, and there is an excess solder mask ink layer between the first window and the PAD window, the mini LED board window opening and finishing method also includes applying black photosensitive ink on the surface of the circuit board corresponding to the PAD window.

[0066] In this embodiment, black photosensitive ink is coated on the surface of the circuit board corresponding to the PAD window. When the laser ablates the excess solder resist layer in the light-transmitting hole, the laser directly contacts the black photosensitive ink. Since the black photosensitive ink has a strong ability to absorb laser light and a weak ability to reflect laser light, the laser energy acts more on the black photosensitive ink, and thus the laser energy acts more on the excess solder resist ink in the PAD window, thereby improving the efficiency of laser ablation of the excess solder resist ink.

[0067] Furthermore, the step of applying black photosensitive ink to the circuit board surface corresponding to the PAD window includes: placing a stencil on the circuit board, the stencil having oil holes formed thereon, the oil holes coinciding with the PAD window; spraying dark photosensitive ink onto the circuit board surface corresponding to the PAD window.

[0068] The present application also provides a method for preparing a mini LED board, including the mini LED board window opening and trimming method described in any of the above embodiments. In one embodiment, the mini LED board window opening and trimming method includes: pre-treating the circuit board to remove the surface oxide of the circuit board; printing the solder resist ink on the surface of the circuit board through a silk screen to form a solder resist layer on the circuit board; baking the circuit board to solidify the solder resist layer; exposing the circuit board; developing the circuit board to form a first window; stacking a light shielding cover on the circuit board, the light shielding cover is formed with a light-transmitting hole, the light-transmitting hole coincides with the PAD window, and there is an excess solder resist ink layer between the first window and the PAD window; laser ablation of the excess solder resist ink layer in the light-transmitting hole to remove the excess solder resist ink layer in the light-transmitting hole.

[0069] In the above-mentioned method for preparing a mini LED board, when the light-shielding cover is stacked on the circuit board, the light-transmitting hole overlaps with the PAD window, so that the excess solder resist layer is still exposed after the light-shielding cover is stacked, so that the excess solder resist layer can be removed. Since the laser burns away the excess solder resist layer in the light-transmitting hole through the light-shielding cover, that is, the laser burns away all the solder resist ink in the PAD window through the PAD window, all the solder resist ink in the PAD window is removed, thereby improving the quality of the PAD window of the circuit board. Moreover, the light-shielding cover blocks the solder resist ink around the PAD window, avoiding accidental burning of the solder resist ink outside the PAD window during laser ablation, and ensuring that the protective effect of the solder resist ink on the circuit is not affected during laser ablation.

[0070] Compared with the prior art, the present invention has at least the following advantages:

[0071] In the above-mentioned mini LED board window trimming method, when the light-shielding cover is stacked on the circuit board, the light-transmitting hole overlaps with the PAD window, so that the excess solder resist layer is still exposed after the light-shielding cover is stacked, so as to remove the excess solder resist layer. Since the laser burns away the excess solder resist layer in the light-transmitting hole through the light-shielding cover, that is, the laser burns away all the solder resist ink in the PAD window through the PAD window, so that all the solder resist ink in the PAD window is removed, thereby improving the quality of the PAD window of the circuit board. In addition, the light-shielding cover blocks the solder resist ink around the PAD window, avoiding accidental burning of the solder resist ink outside the PAD window during laser ablation, and ensuring that the protective effect of the solder resist ink on the circuit is not affected during laser ablation.

[0072] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for opening and trimming a mini LED panel, characterized in that: include: Pre-treating the circuit board to remove surface oxides of the circuit board; Printing solder resist ink on the surface of the circuit board through a silk screen to form a solder resist layer on the circuit board; Performing a baking operation on the circuit board to solidify the solder resist layer; Performing exposure processing on the circuit board; Performing a developing process on the circuit board to form a first window; A light shielding cover is stacked on the circuit board, the light shielding cover comprises a main board body and a reflective layer, the reflective layer is coated and connected to the upper surface of the main board body, the main board body is formed with a through hole, the reflective layer is also coated and connected to the inner wall of the through hole, so that the reflective layer forms a light-transmitting hole in the through hole, and the lower surface of the main board body is in contact with the circuit board; the light-transmitting hole coincides with the PAD window, and there is a redundant solder resist layer between the first window and the PAD window; wherein the size of the light-transmitting hole gradually increases from top to bottom, and the lower edge of the light-transmitting hole coincides with the edge of the PAD window; The excess solder resist layer in the light-transmitting hole is laser ablated, wherein the laser beam is inclined to the surface of the circuit board and ablates along the lower edge of the light-transmitting hole so that the laser acts on the excess solder resist ink corresponding to the edge of the PAD window to remove the excess solder resist layer in the light-transmitting hole.

2. The mini LED panel window opening and trimming method according to claim 1, characterized in that: In the step of printing the solder resist ink on the surface of the circuit board through the screen to form a solder resist layer on the circuit board, the scraper printing speed is set to 2m / min to 3m / min, the scraper thickness is 20mm, and the scraper pressure is 4kg / cm 2 Up to 6kg / cm 2 The scraper hardness is 70A to 75A, the scraper angle is 60 degrees to 80 degrees, and the distance between the screen and the circuit board surface is 2mm to 8mm.

3. The mini LED board window opening and trimming method according to claim 1, characterized in that: The exposure process for the circuit board includes: Measure 9 points of the exposure table surface with a UV energy machine; If the exposure amounts of the nine points are the same, the circuit board is exposed; If the exposure amounts of any two points are different, the exposure machine should be adjusted.

4. The mini LED board window opening and trimming method according to claim 3, characterized in that: Among the 9 points of the exposure surface measured by the UV energy machine, 9 points of the exposure surface are randomly selected for measurement.

5. The mini LED panel window opening and trimming method according to claim 1, characterized in that: In the step of exposing the circuit board, the exposure energy is 8 full grids and the exposure delay is more than 10 seconds.

6. The mini LED panel window opening and trimming method according to claim 1, characterized in that: In the step of baking the circuit board, the baking temperature is 68° C. to 75° C., and the baking time is 16 min to 20 min.

7. The mini LED panel window opening and trimming method according to claim 1, characterized in that: In the step of developing the circuit board to form the first window, the developing pressure is 0.81.2 kg / cm 2 Up to 1.2kg / cm 2 .

8. The mini LED panel window opening and trimming method according to claim 1, characterized in that: The light shielding cover is formed with two alignment holes arranged at intervals, and the two alignment holes are connected with two positioning holes on the circuit board in a one-to-one correspondence.

9. A method for preparing a mini LED board, characterized in that: A miniLED board window opening and trimming method comprising any one of claims 1 to 8.

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