A surface treatment process for LED light board

Abstract

The invention discloses a surface treatment process for an LED light board, comprising the following steps: making a substrate, leaving through holes on the substrate according to a pre-designed drawing; using a plugging pad, the plugging pad is provided with plugging holes corresponding to the through holes of the substrate one by one, and the plugging pad is placed under the substrate; using a plugging machine to inject plugging ink into designated through holes and plugging holes at the through hole positions, and making the upper surface of the plugging ink higher than the upper surface of the substrate; using an automatic sprayer and a screen printing device to evenly coat liquid solder resist on the upper surface of the substrate, and using the screen printing device to print a pre-designed pattern on the upper surface of the substrate; using an inkjet printer to accurately spray printing ink onto the upper surface of the substrate to form clear text or identification information; and spraying tin, using a tin spraying machine to cover a uniform layer of solder on the copper pad of the substrate; this surface treatment process for an LED light board facilitates plugging holes and avoids material entry into the holes caused by a subsequent tin spraying process.

Description

Technical Field

[0001] The invention specifically relates to a surface treatment process for an LED lamp panel. Background Art

[0002] With the rapid development of LED lighting technology, LED light boards, as one of the core components, are mainly composed of PCB boards and have been widely used in various lighting products. In order to ensure the performance stability and reliability of LED light boards in long-term use, its surface treatment process is particularly important. Good surface treatment can not only improve the welding quality, but also effectively prevent the influence of external environmental factors (such as moisture, dust, etc.) on the circuit and extend the service life of the product. The traditional surface treatment process of LED light boards mainly includes the following steps: substrate production, silk screen printing solder resist and tin spraying. Since LED light boards are generally provided with various functional through holes to meet the positioning, installation and other functions during the processing process, these functional holes are prone to cause tin beads to enter the functional holes during the tin spraying process, which in turn causes poor product quality and even functional defects.

[0003] The present invention is just produced based on the above-mentioned shortcomings. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and to provide a surface treatment process for an LED lamp panel which is convenient for plugging holes and avoids the subsequent tin spraying process causing material to enter the holes.

[0005] The present invention is achieved through the following technical solutions:

[0006] A surface treatment process for an LED light panel includes the following steps:

[0007] S1, making a substrate, leaving through holes on the substrate according to a pre-designed drawing;

[0008] S2, a pad, using a plugging pad, the plugging pad is provided with plugging holes corresponding to the through holes of the substrate, and the plugging pad is placed under the substrate;

[0009] S3, screen printing plugging, using a plugging machine to inject plugging ink into the designated through-hole and plugging hole at the through-hole position, and make the upper surface of the plugging ink higher than the upper surface of the substrate;

[0010] S4, screen printing panel, use automatic spray machine and screen printing equipment to evenly apply liquid solder resist on the upper surface of the substrate, and use screen printing equipment to print the pre-designed pattern on the upper surface of the substrate;

[0011] S5, printing characters, using an inkjet printer to accurately spray printing ink onto the upper surface of the substrate to form clear text or identification information;

[0012] S6. Spray tin. Use a tin spray machine to cover the copper pad of the substrate with a uniform layer of solder.

[0013] The LED light board surface treatment process as described above further includes the following steps between steps S4 and S5:

[0014] S4-1, pre-baking, the baking temperature is 65°C to 85°C, and the baking time is 45min to 50min;

[0015] S4-2, exposure and development, placing the substrate printed with solder resist into an ultraviolet UV exposure machine to cause a chemical reaction in the photoinitiator in the solder resist to solidify the solder resist, and then removing the solder resist in the unexposed part through a development process to expose the copper pad to be soldered;

[0016] In the above-mentioned surface treatment process of the LED lamp panel, in step S3, the viscosity of the plugging ink is 400 dpa.s, and in step S4, the viscosity of the ink during screen printing is 110 dpa.s.

[0017] The above-mentioned surface treatment process of the LED light board is characterized in that: the plugging ink adopts the industrial photosensitive solder resist material of model RS-2000BKM (PF):

[0018] The above-mentioned LED lamp panel surface treatment process, after step S5, further includes the following steps:

[0019] S5-1, character post-bake, bake the substrate, the baking process is: first bake at 60℃ for 60min, then bake at 70℃ for 30min, then bake at 90℃ for 30min, then bake at 110℃ for 30min, and then bake at 150℃ for 60min.

[0020] The above-mentioned LED light board surface treatment process, before step S1, further includes the following steps:

[0021] S0-1, grinding, grinding and removing excess material on the surface of the substrate to achieve the required flatness and thickness requirements;

[0022] S0-2, pickling, using a 4% concentration acid solution to remove oxides or impurities on the surface of the substrate;

[0023] S0-3, volcanic ash cleaning, spray 21% volcanic ash cleaner onto the substrate surface, and remove surface oxides and other impurities by slight friction;

[0024] S0-4, drying, the baking temperature is 90°C, and baking is performed until the substrate is dry.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] The surface treatment process of the LED lamp board provided by the present invention has a concise and clear process flow. In the process flow, a plugging pad can be first placed under the substrate, and the through hole of the substrate is connected to the corresponding plugged hole, so that the plugging ink can enter the through hole and the plugged hole in the subsequent steps. In this way, after the substrate leaves the plugging pad, the through hole is filled with plugging ink, and at the same time, the plugging ink at the lower end of the through hole protrudes downward, and the plugging ink at the upper end of the through hole protrudes upward. In this way, in the subsequent ink curing process, the originally protruding material shrinks due to the ink curing, so that the upper and lower ends of the plugging ink in the final through hole are as flush as possible with the upper and lower surfaces of the substrate, avoiding material loss and material concavity, which leads to the tin-spraying material entering the through hole in the subsequent tin-spraying process, and then the tin beads of the tin-spraying can be prevented from entering the through hole, thereby improving the quality and stability of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of the LED light board of the present invention;

[0028] Figure 2 It is a schematic diagram of the principle of the surface treatment process of the LED light board of the present invention;

[0029] Figure 3 yes Figure 2 Continuation of . DETAILED DESCRIPTION

[0030] The invention will be further described below in conjunction with the accompanying drawings:

[0031] The directions described in the specification of the present invention, such as "up", "down", "left", "right", "front", "back", etc., are based on the directions of the drawings and are intended to facilitate the description of the relationship between the various components. They do not indicate the unique or absolute positional relationship between the various components. They are only one of the implementation methods of the invention and are not a limitation on its implementation method.

[0032] This embodiment provides a surface treatment process for an LED lamp panel. Figure 1 and Figure 2 , including the following steps:

[0033] A surface treatment process for an LED light panel, the method and steps are as follows:

[0034] The following are the pre-processing steps. The pre-processing includes steps S0-1 to S0-4. The pre-processing is for cleaning the substrate in advance, and the pre-processing steps may not be performed.

[0035] S0-1, grinding, grinding and removing excess material on the surface of the substrate 1 to achieve the required flatness and thickness requirements, placing the substrate 1 on the workbench of the grinding machine to ensure that it is fixed in position, and using a grinding tool (such as a grinding wheel or a diamond belt) to perform rough grinding to fine grinding to achieve the precise target thickness and ensure that the surface is smooth and flat, wherein the grinding tool speed is controlled at 3.5m / min.

[0036] S0-2, pickling, using a 4% concentration acid solution to remove oxides or impurities on the surface of the substrate 1, wherein the selectable solutions include sulfuric acid (H2SO4), which is often used to remove oxides on the copper surface and has strong corrosiveness and oxidizing ability; hydrochloric acid (HCl): suitable for removing rust and other metal oxides, and also has a certain effect on copper; nitric acid (HNO3), mainly used to remove organic pollutants and certain metal oxides, and also has strong oxidizing properties; mixed acid: sometimes a mixture of multiple acids is used according to specific needs to achieve a better cleaning effect.

[0037] S0-3, volcanic ash cleaning, spray a 21% volcanic ash cleaner onto the surface of the substrate 1, remove the oxides and other impurities on the surface by slight friction, spray the cleaner containing volcanic ash onto the surface of the copper foil, or use a brush with volcanic ash to scrub. When the volcanic ash particles come into contact with the surface of the copper foil, they will remove the oxides and other impurities on the surface by slight friction. The volcanic ash treatment can also slightly increase the roughness of the copper foil surface, which helps to improve the adhesion in subsequent processes, such as copper plating or lamination.

[0038] S0-4, baking, the baking temperature is between 90° C. and 100° C., preferably 95° C., and baking is performed until the substrate 1 is dry.

[0039] The process control parameters in the pre-treatment step are as follows:

[0040]

[0041] The basic steps are as follows. The basic steps include steps S1 to S6.

[0042] S1, manufacturing a substrate 1, leaving a through hole 11 on the substrate 1 according to a pre-designed drawing, the through hole being a functional hole for positioning, mounting or copper deposition;

[0043] S2, pad, using a plugging pad 2, the plugging pad 2 is provided with a through hole that is one-to-one with the substrate. The following are the basic steps, the basic steps include steps S1 to S6

[0044] S1, manufacturing a substrate 1, leaving a through hole 11 on the substrate 1 according to a pre-designed drawing, the through hole being a functional hole for positioning, mounting or copper deposition;

[0045] S2, a pad, using a plugging pad 2, on which a plugging hole 21 corresponding to the through hole of the substrate is provided, and the plugging pad 21 is placed under the substrate 1 so that the through hole 11 of the substrate 1 is connected with the corresponding plugging hole 21;

[0046] S3, screen printing plugging, using a plugging machine to inject plugging ink a into the designated through hole 11 and the plugging hole 21 at the through hole position, and make the upper surface of the plugging ink higher than the upper surface of the substrate, such as Figure 1 As shown, the plugging ink a is poured into the plugging hole 21, while the ink in the through hole 11 bulges upward and is higher than the opening of the through hole 11.

[0047] S4, screen printing panel, use automatic spray machine and screen printing equipment to evenly apply liquid solder resist on the upper surface of the substrate, and use screen printing equipment to print the pre-designed pattern on the upper surface of the substrate;

[0048] In steps S3 and S4, the process control parameters are as follows:

[0049]

[0050] S4-1, pre-baking, the baking temperature is 65°C to 85°C, and the baking time is 45min to 50min;

[0051] S4-2, exposure and development, placing the substrate printed with solder resist into an ultraviolet UV exposure machine to cause a chemical reaction in the photoinitiator in the solder resist to solidify the solder resist, and then removing the solder resist in the unexposed part through a development process to expose the copper pad to be soldered;

[0052] In steps S4-1 and S4-2, the process control parameters are as follows:

[0053]

[0054] S5, printing characters, using an inkjet printer to accurately spray printing ink onto the upper surface of the substrate to form clear text or identification information;

[0055] In step S5, the control parameters of the inkjet printer are as follows:

[0056] project Require Air source check 0.6±0.1Mpa Sticky paper replacement 1 time / 200PNL Nozzle temperature 50±5℃ Nozzle voltage 14±2V Cleaning Nozzle 20 sides cleaning 20S

[0057] S5-1, character post-bake, bake the substrate, the baking process is: first bake at 60℃ for 60min, then bake at 70℃ for 30min, then bake at 90℃ for 30min, then bake at 110℃ for 30min, and then bake at 150℃ for 60min.

[0058] S6, tin spraying, using a tin spraying machine to cover the copper pad of the substrate with a uniform layer of solder;

[0059] In step S5, the control parameters of the tin spraying machine are as follows:

[0060]

[0061] Through the above-mentioned step S2, the pad is used, and the through hole 11 of the substrate 1 is connected with the corresponding plugging hole 21, so that the plugging ink a can enter the through hole 11 and the plugging hole 21 in step S3. In this way, after the substrate 1 leaves the plugging pad 2, the through hole 11 is filled with the plugging ink a, and at the same time, the plugging ink a at the lower end of the through hole 11 protrudes downward, and the plugging ink a at the upper end of the through hole 11 protrudes upward. In this way, in the subsequent ink curing process, the originally protruding material shrinks due to the ink curing, so that the upper and lower ends of the plugging ink a in the through hole 11 are finally flush with the upper and lower surfaces of the substrate 1 as much as possible, avoiding material loss and material concavity, which will cause the tin-spraying material to enter the through hole 11 in the subsequent tin-spraying process, and then the tin beads of the tin-spraying can be prevented from entering the through hole 11, thereby improving the quality and stability of the product.

[0062] Preferably, the plugging ink is a commercial photosensitive solder resist material of model RS-2000BKM (PF).

[0063] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A surface treatment process for LED light panels, characterized in that: The following steps are included: S1, making a substrate, leaving through holes on the substrate according to a pre-designed drawing; S2, a pad, using a plugging pad, the plugging pad is provided with plugging holes corresponding to the through holes of the substrate, and the plugging pad is placed under the substrate; S3, screen printing plugging, using a plugging machine to inject plugging ink into the designated through-hole and plugging hole at the through-hole position, and make the upper surface of the plugging ink higher than the upper surface of the substrate; S4, screen printing panel, use automatic spray machine and screen printing equipment to evenly apply liquid solder resist on the upper surface of the substrate, and use screen printing equipment to print the pre-designed pattern on the upper surface of the substrate; S5, printing characters, using an inkjet printer to accurately spray printing ink onto the upper surface of the substrate to form clear text or identification information; S6. Spray tin. Use a tin spray machine to cover the copper pad of the substrate with a uniform layer of solder.

2. The surface treatment process of the LED light board according to claim 1, characterized in that: The following steps are also included between steps S4 and S5: S4-1, pre-bake, the baking temperature is 65℃ to 85℃, and the baking time is 45min to 50min; S4-2, exposure and development, put the substrate printed with solder resist into an ultraviolet UV exposure machine to make the photoinitiator in the solder resist undergo a chemical reaction to solidify the solder resist, and then remove the solder resist in the unexposed part through the development process to expose the copper pads that need to be soldered.

3. The surface treatment process of the LED light board according to claim 1, characterized in that: In step S3, the viscosity of the plugging ink is 400 dpa.s, and in step S4, the viscosity of the ink during screen printing is 110 dpa.s.

4. The surface treatment process of the LED light board according to claim 1, characterized in that: The plugging ink is a commercial photosensitive solder resist material with a model number of RS-2000BKM (PF).

5. The surface treatment process of the LED light board according to claim 1, characterized in that: After step S5, the following steps are also included: S5-1, character post-bake, bake the substrate, the baking process is: first bake at 60℃ for 60min, then bake at 70℃ for 30min, then bake at 90℃ for 30min, then bake at 110℃ for 30min, and then bake at 150℃ for 60min.

6. The surface treatment process of the LED light board according to claim 1, characterized in that: Before step S1, the following steps are also included: S0-1, grinding, grinding and removing excess material on the surface of the substrate to achieve the required flatness and thickness requirements; S0-2, pickling, using 4% acid solution to remove oxides or impurities on the substrate surface; S0-3, volcanic ash cleaning, spraying 21% volcanic ash cleaner onto the substrate surface, removing oxides and other impurities on the surface through slight friction; S0-4, drying, the baking temperature is 95°C, and the substrate is baked until it is dry.

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