Coating, method for preparing coating, and device

Abstract

The embodiment of the invention provides a coating, a preparation method of the coating and a device. The preparation method of the coating comprises the steps that a base material is placed on a support in a plasma reaction chamber; activating gas is introduced, first plasma discharge is started, and the base material is pretreated; an organic silicon monomer is introduced into the plasma reaction chamber, second plasma discharge is started, bias voltage is loaded on the support, and a coating with the thickness ranging from 400 nm to 2000 nm is deposited on at least part of the surface of the base material. The coating has excellent light transmission performance, anti-vulcanization performance and environmental aging resistance.

Description

Technical Field

[0001] The present disclosure relates to the field of chemical protective coatings, and in particular to a coating, a method for preparing the coating, and a device. Background Art

[0002] As a commonly used light-emitting device, light-emitting diode (LED) can realize the efficient conversion of electrical energy and light energy by releasing energy through the recombination of electrons and holes. LED is widely used in many fields due to its advantages such as high efficiency, long service life, environmental friendliness, fast response, color diversity, intelligent control and cost reduction with technological progress. In the field of display screens, LED is widely used in televisions, computers, mobile phones and advertising screens; in the field of lighting, LED is used for general lighting, automotive lighting and decorative lighting; in the field of signal systems and information boards, LED is often used for traffic lights, emergency vehicle photos and information display boards; in addition, LED is also used in special fields such as medical equipment, remote controls, plant growth lights, etc. However, during the production and use of LED, it is necessary to protect it, especially to avoid contact with sulfide gas, which may react chemically with LED, resulting in performance degradation, such as reduced luminous flux, color temperature drift, shortened life, and even failure.

[0003] During the production and use of LED products, they are sometimes exposed to sulfide gas environments. Common anti-sulfide measures include selecting anti-sulfide LED materials, optimizing product structure design to improve anti-sulfide performance from a mechanical structure perspective, and improving product sealing to reduce the impact of sulfide gas. However, these measures are difficult to completely isolate sulfide gas in practice, and there are often many problems. For example, using phenyl glue as a packaging material will increase production costs; using organic gas barrier materials to protect LED lamp beads will result in degradation under high temperature conditions, molecular fission and cracking. Summary of the invention

[0004] To solve the above problems, an embodiment of the present disclosure provides a method for preparing a coating, the preparation method comprising: placing a substrate on a bracket in a plasma reaction chamber; introducing an activated gas, starting a first plasma discharge, and pre-treating the substrate; introducing an organosilicon monomer into the plasma reaction chamber, starting a second plasma discharge, and loading a bias voltage on the bracket to deposit a coating with a thickness of 400nm to 2000nm on at least a portion of the surface of the substrate.

[0005] In some embodiments, the bias voltage ranges from 100V to 800V.

[0006] In some embodiments, loading the stent with a bias comprises: loading the stent with biases of different magnitudes in at least a first time period and a second time period.

[0007] In some embodiments, a bias voltage of 100V to 400V is loaded on the bracket in the first time period, and the duration of the first time period is 10min to 60min; a bias voltage of 400V to 800V is loaded on the bracket in the second time period, and the duration of the second time period is 5min to 30min.

[0008] In some embodiments, the second time period is after the first time period.

[0009] In some embodiments, during the process of depositing the coating, the power of the second plasma discharge is 50W to 500W, and the deposition time is 8min to 90min.

[0010] In some embodiments, in the pretreatment, the power of the first plasma discharge is 100W to 600W, and the duration of the first plasma discharge is 5min to 30min.

[0011] In some embodiments, the first plasma discharge and / or the second plasma discharge is an ICP discharge.

[0012] In some embodiments, the first plasma discharge and / or the second plasma discharge is a continuous discharge.

[0013] In some embodiments, the step of introducing the organosilicon monomer into the plasma reaction chamber includes: introducing the organosilicon monomer and a reaction gas into the plasma reaction chamber, wherein the reaction gas includes one or more of oxygen, argon, helium and hydrogen, the flow rate of the organosilicon monomer is 10 μL / min to 500 μL / min, and the flow rate of the reaction gas is 50 sccm to 500 sccm.

[0014] In some embodiments, the coating has a thickness of 400 nm to 500 nm.

[0015] In some embodiments, the organosilicon monomer comprises at least one of the structures shown in the following formula (1) or (2):

[0016]

[0017] In formula (1), R 1 , R 2 and R 3 are independently selected from hydrogen atoms, C 1 -C 12Substituted or unsubstituted alkyl, C 1 -C 12 Substituted or unsubstituted alkoxy, or C 1 -C 12 A substituted or unsubstituted alkylsilyl group, wherein R 1 , R 2 and R 3 At least one of them is not a hydrogen atom, R 4 C 1 -C 12 Substituted or unsubstituted alkyl, or C 1 -C 12 wherein X is selected from an oxygen atom, a nitrogen atom or a connecting bond, and n is an integer from 1 to 100; or (2), R 5 and R 6 are independently selected from hydrogen atoms, C 1 -C 12 Substituted or unsubstituted alkyl, C 1 -C 12 Substituted or unsubstituted alkoxy, or C 1 -C 12 A substituted or unsubstituted alkylsilyl group, wherein R 5 or R 6 At least one of them is not a hydrogen atom, Y is selected from an oxygen atom or a nitrogen atom, and m is an integer of 3 to 10.

[0018] In some embodiments, the R 1 , R 2 and R 3 are independently selected from methyl, ethyl, trimethylsilyloxy, triethylsilyloxy or hydrogen atom, wherein R 4 is methyl, ethyl, trimethylsilyl or triethylsilyl, X is selected from oxygen atom or nitrogen atom, n is an integer of 1 to 20; R 5 and R 6 They are independently selected from a hydrogen atom, a methyl group or an ethyl group, and m is an integer of 3 to 6.

[0019] In some embodiments, the R 5 and R 6 is selected from a methyl group, the Y is selected from an oxygen atom, and m is an integer of 3 to 5.

[0020] In some embodiments, the organosilicon monomer includes one or more of hexamethyldisilazane, hexamethyldisiloxane, polymethylhydrogensiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane.

[0021] In some embodiments, the substrate includes a light emitting device.

[0022] In some embodiments, the light emitting device includes an LED substrate, and the LED substrate includes: an LED lamp, an LED display screen, or an LED bracket.

[0023] The disclosed embodiment also provides a coating, which is a plasma polymerization coating of silicone, the thickness of the coating is 400nm to 2000nm, and after the coating is exposed to 1.3mg / mL sulfur powder and 85°C for 8 hours, the reduction value of the luminous flux of the coating is less than 3%.

[0024] In some embodiments, after the coating is exposed to 1.3 mg / mL sulfur powder and 85° C. for 8 hours, the reduction value of the luminous flux of the coating is less than 2.5%.

[0025] In some embodiments, the coating has a thickness of 400 nm to 500 nm.

[0026] In some embodiments, the coating is prepared by any of the above coating preparation methods.

[0027] The embodiments of the present disclosure also provide a device, wherein at least a portion of the surface of the device is formed with any of the above coatings.

[0028] Compared with the prior art, the technical solution of the embodiment of the present disclosure has the following beneficial effects:

[0029] The method for preparing the coating of the embodiment of the present disclosure is as follows: introducing an activated gas, starting a first plasma discharge, not loading a bias voltage on a bracket on which a substrate is placed, and pretreating the substrate; introducing an organosilicon monomer into the plasma reaction chamber, starting a second plasma discharge, and loading a bias voltage on a bracket placed on the substrate, and depositing a coating with a thickness of 400nm to 2000nm on at least a portion of the surface of the substrate, wherein the coating has excellent light transmittance, anti-sulfurization performance, and environmental aging resistance.

[0030] The coating of the disclosed embodiment is a plasma polymerization coating of silicone, the thickness of the coating is 400nm to 2000nm, and after being exposed to 1.3mg / mL sulfur powder and 85°C for 8 hours, the reduction value of the luminous flux of the coating is less than 3%, and the coating has excellent anti-sulfurization performance. DETAILED DESCRIPTION

[0031] The inventors have found that, by using PECVD to prepare a plasma polymerization coating of silicone, firstly, an activated gas is introduced, plasma discharge is started but no bias voltage is loaded, and the substrate is pretreated; then, an silicone monomer is introduced, plasma discharge is started, and a bias voltage is loaded on the bracket where the substrate is placed, to prepare a coating having excellent light transmittance, anti-sulfurization performance, and environmental aging resistance.

[0032] A specific embodiment of the present disclosure provides a method for preparing a coating, which includes: placing a substrate on a bracket in a plasma reaction chamber; introducing an activated gas, starting a first plasma discharge, and pre-treating the substrate; introducing an organic silicon monomer into the plasma reaction chamber, starting a second plasma discharge, and loading a bias voltage on the bracket to deposit a coating with a thickness of 400nm to 2000nm on at least a portion of the surface of the substrate.

[0033] The preparation method of the specific embodiment of the present disclosure avoids the coating being too thin and having insufficient protective effect, and avoids the coating being too thick and causing problems such as coating cracks due to factors such as stress, and the thickness of the coating is 400nm to 2000nm. In some specific embodiments, the thickness of the coating is 400nm to 1500nm; in some specific embodiments, the thickness of the coating is 400nm to 1000nm; in some specific embodiments, the thickness of the coating is 400nm to 500nm, for example, it can be 400nm, 410nm, 415nm, 425nm, 431nm, 450nm, 460nm, 470nm, 480nm, 490nm or 500nm, etc.; in some specific embodiments, the thickness of the coating is 400nm to 450nm; in some specific embodiments, the thickness of the coating is 410nm to 440nm.

[0034] In the preparation method of the specific embodiment of the present invention, during the deposition process to form the coating, in order to avoid damage to the substrate due to excessive bias, in some specific embodiments, the bias voltage loaded on the bracket is 100V to 800V, for example, it can be 200V, 250V, 300V, 350V, 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V or 800V, etc.

[0035] In some specific embodiments, an organosilicon monomer is introduced into a plasma reaction chamber, a second plasma discharge is started, and a bias voltage is applied to the bracket. The specific bias loading method is as follows: different bias voltages are applied to the bracket in at least a first time period and a second time period, respectively; since the power of the second plasma discharge remains unchanged during the deposition of the coating, film layers with different microstructures are deposited under bias voltages of different magnitudes, thereby depositing at least two stacked film layers on at least a portion of the surface of the substrate, and the void structures and densities in different film layers are different, and the voids in one film layer are offset from the voids in an adjacent film layer, thereby making it more difficult for gas molecules or liquid molecules to penetrate the film layer, so that the coating as a whole exhibits better protective performance.

[0036] In some specific embodiments, loading the bracket with a bias further includes: loading the bracket with a bias of 100V to 400V in a first time period, the duration of the first time period is 10min to 60min; loading the bracket with a bias of 400V to 800V in a second time period, the duration of the second time period is 5min to 30min.

[0037] In some embodiments, the first time period and the second time period are adjacent.

[0038] In some specific embodiments, the second time period follows the first time period. A relatively small bias voltage is first loaded in the first time period. The ratio of carbon atoms to silicon atoms in the film layer formed under the small bias voltage is relatively high, the internal stress of the film layer is small, and it is not easy to crack and cause the film layer structure to be destroyed. A relatively large bias voltage is loaded in the second time period to increase the deposition rate of the coating. The ratio of carbon atoms to silicon atoms in the film layer is relatively low, and the film layer has good anti-sulfurization properties, and finally a coating consisting of two film layers is formed. The film layer formed in the first time period has a lower internal stress and can transition and buffer the internal stress of the film layer formed in the second time period, so that the overall structure of the coating is more stable.

[0039] In some specific embodiments, bias loading on the stent includes: loading biases of different magnitudes on the stent in three or more time periods, the bias loaded in each time period being different in magnitude from the bias loaded in the adjacent time period, so that the gaps in adjacent film layers are mutually misaligned, thereby improving the overall anti-permeability effect of the coating. In some specific embodiments, the stent is first biased in the first time period, then biased in the second time period, and finally biased in the third time period, the magnitude of the bias loaded in the second time period is different from the magnitude of the bias loaded in the first time period and the third time period, and the magnitude of the bias loaded in the first time period and the third time period may be the same or different.

[0040] In the preparation method of the specific embodiments of the present disclosure, in some specific embodiments, the bracket is a rotatable turntable. During the process of depositing the coating, the bracket can rotate, which is beneficial to improving the uniformity of the deposited coating on the substrate; in some specific embodiments, the bracket is suitable for rotating around its center. Further, the bracket can be a planetary turntable, so that the substrate is displaced relative to the bracket while following the bracket to rotate around the center of the bracket, which is beneficial to improving the uniformity of the deposited coating.

[0041] In some specific embodiments of the preparation method of the specific embodiments of the present disclosure, during the process of introducing the organic silicon monomer for deposition to form the coating, the discharge mode of the second plasma discharge is continuous discharge or pulse discharge.

[0042] In some specific embodiments, during the process of introducing the organic silicon monomer to deposit and form the coating, the second plasma discharge is an ICP (inductively coupled plasma) discharge.

[0043] In some specific embodiments, during the process of introducing the organic silicon monomer for deposition to form the coating, the second plasma discharge mode adopts continuous discharge, and the power of the second plasma discharge is 50W to 500W, for example, it can be 50W, 80W, 100W, 120W, 140W, 160W, 180W, 200W, 220W, 240W, 260W, 280W, 300W, 320W, 340W, 360W, 380W, 400W, 420W, 440W, 460W, 480W or 500W; the deposition time is 8min to 90min, for example, it can be 8min, 10min, 15min, 20min, 25min, 28min, 30min, 35min, 40min, 45min, 50min, 55min, 60min, 65min, 70min, 75min, 80min, 85min or 90min, etc.

[0044] In some specific embodiments of the preparation method of the specific embodiments of the present disclosure, the step of passing an organosilicon monomer into a plasma reaction chamber to deposit and form a coating comprises: evacuating the plasma reaction chamber to a pressure of 0.5 to 5 Pa, passing the organosilicon monomer and a reaction gas into the plasma reaction chamber, starting a second plasma discharge, and loading a bias voltage on the bracket.

[0045] In some embodiments, the reaction gas includes one or more of oxygen, argon, helium and hydrogen.

[0046] In some specific embodiments, the flow rate of the organic silicon monomer is 10 μL / min to 500 μL / min, and the flow rate of the reaction gas is 50 sccm to 500 sccm.

[0047] In some specific embodiments of the preparation method of the specific embodiments of the present disclosure, when pre-treating the substrate, the pressure in the plasma reaction chamber is evacuated to 0.5-5 Pa, an activation gas is introduced at a flow rate of 20-200 sccm, and the first plasma discharge is started to allow the plasma to bombard the substrate to activate the substrate, which is beneficial to improving the bonding strength between the subsequently formed coating and the substrate.

[0048] In some embodiments, the activated gas includes He, Ar, O 2 One or a mixture of gases.

[0049] In the preparation method of the specific embodiment of the present disclosure, continuous discharge or pulse discharge can be used in the pretreatment stage. In some specific embodiments, in the pretreatment stage, the first plasma discharge is continuous discharge, and the discharge power is 100-600W, for example, 100W, 120W, 140W, 160W, 180W, 190W, 200W, 210W, 220W, 230W, 240W, 250W, 260W, 270W, 280W, 290W, 300W, 400W, 500W or 600W, etc.; the discharge time is 5min-30min, for example, 5min, 10min, 15min, 20min, 25min or 30min, etc.

[0050] In some embodiments, during the pretreatment stage, the first plasma discharge is an ICP discharge.

[0051] It should be noted that the first plasma discharge and the second plasma discharge may be provided by the same or different power sources, for example, by the same ICP source. In some specific embodiments, the power of the first plasma discharge and the power of the second plasma discharge may be the same or different.

[0052] In some specific embodiments, the preparation method of the specific embodiment of the present disclosure further includes post-processing, and the post-processing includes: after depositing the coating on at least part of the surface of the substrate, introducing clean compressed air or inert gas to restore the plasma reaction chamber to normal pressure, opening the plasma reaction chamber, and removing the substrate. In some specific embodiments, the inert gas is introduced, and the flow rate of the inert gas is 5 to 300 sccm.

[0053] In the preparation method of the specific embodiment of the present disclosure, in some specific embodiments, the organosilicon monomer includes at least one of the structures shown in the following formula (1) or (2):

[0054]

[0055] In formula (1), R 1 , R 2 and R 3 are independently selected from hydrogen atoms, C 1 -C 12 Substituted or unsubstituted alkyl, C 1 -C 12 Substituted or unsubstituted alkoxy, or C 1 -C 12 Substituted or unsubstituted alkylsilyloxy groups, R 1 , R 2 and R 3 At least one of them is not a hydrogen atom, R 4 C1 -C 12 Substituted or unsubstituted alkyl, or C 1 -C 12 A substituted or unsubstituted alkylsilyl group, X is selected from an oxygen atom, a nitrogen atom or a connecting bond, and n is an integer from 1 to 100;

[0056] Or (2), R 5 and R 6 are independently selected from hydrogen atoms, C 1 -C 12 Substituted or unsubstituted alkyl, C 1 -C 12 Substituted or unsubstituted alkoxy, or C 1 -C 12 Substituted or unsubstituted alkylsilyloxy groups, R 5 or R 6 At least one of them is not a hydrogen atom, Y is selected from an oxygen atom or a nitrogen atom, and m is an integer of 3 to 10.

[0057] In some specific embodiments, in formula (1), R 1 , R 2 and R 3 are independently selected from hydrogen atoms, C 1 -C 6 Substituted or unsubstituted alkyl, C 1 -C 6 Substituted or unsubstituted alkoxy, or C 1 -C 6 A substituted or unsubstituted alkylsilyl group; R 4 C 1 -C 6 Substituted or unsubstituted alkyl, or C 1 -C 6 A substituted or unsubstituted alkylsilyl group; further, R 1 , R 2 and R 3 are independently selected from hydrogen atoms, C 1 -C 6 Alkyl, C 1 -C 6 Alkoxy, or C 1 -C 6 Alkylsilyl group; R 4 C 1 -C 6 Alkyl or C 1 -C 6 Alkylsilyl.

[0058] In some specific embodiments, in formula (1), R 1 , R 2 and R3 are independently selected from methyl, ethyl, trimethylsilyloxy, triethylsilyloxy or hydrogen atom, R 4 is methyl, ethyl, trimethylsilyl or triethylsilyl, X is selected from oxygen atom or nitrogen atom, and n is an integer of 1 to 20.

[0059] In some specific embodiments, in formula (2), R 5 and R 6 are independently selected from hydrogen atoms, C 1 -C 6 Substituted or unsubstituted alkyl, C 1 -C 6 Substituted or unsubstituted alkoxy, or C 1 -C 6 A substituted or unsubstituted alkylsilyl group; further, R 5 and R 6 are independently selected from hydrogen atoms, C 1 -C 4 Alkyl, C 1 -C 4 Alkoxy, or C 1 -C 4 Alkylsiloxy.

[0060] In some specific embodiments, in formula (2), R 5 and R 6 are independently selected from hydrogen, methyl or ethyl, and m is an integer of 3 to 6; in some embodiments, R 5 and R 6 is selected from a methyl group, the Y is selected from an oxygen atom, and m is an integer of 3 to 5.

[0061] In some specific embodiments, the organosilicon monomer includes one or more of hexamethyldisilazane, hexamethyldisiloxane, polymethylhydrogensiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane.

[0062] In some specific embodiments, the organosilicon monomer includes one or more of hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane.

[0063] In the preparation method of the specific embodiments of the present disclosure, in some specific embodiments, the substrate includes a light-emitting device. In some specific embodiments, the light-emitting device includes an LED substrate, and the LED substrate includes: an LED light-emitting part and a non-light-emitting part such as an LED lamp, an LED display, or an LED bracket; the LED lamp can be in the shape of a plate, such as an LED lamp board, or in the shape of a sphere, such as an LED lamp bead, or in other shapes. In some specific embodiments, the light-emitting device can also be an OLED device, a micro LED device, and the like.

[0064] The coating prepared by the preparation method of the specific embodiment of the present disclosure has no discoloration, gel cracking, or detachment from the substrate after being exposed to 1.3 mg / mL sulfur powder and 85°C for 8 hours, and the reduction in the luminous flux of the coating is less than 3%. In some specific embodiments, the reduction in the luminous flux of the coating is less than 2.5%; further, less than 2%; further, less than 1.5%; further, less than 1%. The prepared coating has excellent anti-sulfurization performance and has a good protective effect on the substrate in the environment of sulfiding gas, especially for the substrate of the light-emitting device. After the coating is formed, the luminous flux of the substrate itself is not affected, and the reduction in the luminous flux in the sulfiding environment is low.

[0065] The specific embodiment of the present disclosure also provides a coating, which is a plasma polymerization coating of silicone, the thickness of the coating is 400nm to 2000nm, and after the coating is exposed to 1.3mg / mL sulfur powder and 85°C for 8 hours, the reduction value of the luminous flux of the coating is less than 3%.

[0066] In some specific embodiments, after the coating is exposed to 1.3 mg / mL sulfur powder and 85°C for 8 hours, the reduction in luminous flux of the coating is less than 2.5%; further, less than 2%; further, less than 1.5%; further, less than 1%.

[0067] In some embodiments, the coating has a thickness of 400 nm to 500 nm.

[0068] In some specific embodiments, the coating is prepared by the preparation method of any of the above specific embodiments.

[0069] In some specific embodiments of the coating disclosed herein, the coating includes at least two film layers, and each film layer is formed sequentially under conditions of different bias voltages loaded on a bracket; in some specific embodiments, the coating composed of at least two film layers, after 8 hours in an environment of 1.3 mg / mL sulfur powder and 85°C temperature, has no discoloration, gel cracking, or detachment from the substrate, and the reduction value of the luminous flux of the coating is less than 1%.

[0070] In some embodiments, the coating of the specific embodiments of the present disclosure has no surface defects after being placed in an environment at a temperature of 85°C and a humidity of 85%RH for 1000 hours; in some embodiments, a light-emitting device having the coating formed on the surface thereof has no problems such as color deficiency, dead light (failure to light up), etc. after being placed in an environment at a temperature of 85°C and a humidity of 85%RH for 1000 hours. The surface coating has excellent environmental aging resistance.

[0071] The specific embodiments of the present disclosure also provide a device, at least a portion of the surface of the device is formed with a coating according to any of the above specific embodiments.

[0072] In some specific embodiments, the device is a light-emitting device, such as an LED device. The coating formed on at least a portion of the surface of the light-emitting device has excellent light transmittance. After the coating is formed, it does not affect the luminous flux of the device itself. The coating has excellent anti-sulfurization performance and environmental aging resistance. It has a good protective effect on the device in a sulfiding gas environment and a high temperature and high humidity environment. The reduction value of the luminous flux in the sulfiding environment is low, and does not affect the luminescence and use of the device.

[0073] The present disclosure is further described below through specific embodiments.

[0074] Example

[0075] Test Method Description

[0076] Thickness: measured using the American Filmetrics F20-UV-film thickness meter;

[0077] Anti-sulfurization test: (1) After 8 hours in an environment with 1.3 mg / mL sulfur powder and a temperature of 85°C, observe whether the LED substrate has black, cracked, or fallen off. The specific process includes: taking 0.26g of sulfur powder and placing it in a 25mL beaker, placing the 25mL beaker in a 200mL beaker, placing the coated LED substrate in the 200mL beaker, sealing the 200mL beaker, and placing the beaker in an oven at a temperature of 85°C for 8 hours, and observing whether the substrate has black, cracked, or fallen off. (2) Before and after (1), test the luminous flux of the LED substrate and calculate the reduction in luminous flux after the anti-sulfurization test.

[0078] High temperature and high humidity test: Zhenghang's ZH-CTH-225D constant temperature and humidity chamber is used for testing. The test conditions are temperature 85℃ and humidity 85% RH. After 1000 hours, the LED substrate is lit to observe whether there are problems such as dead lights and color deficiency. If there are no problems, the test results are recorded as qualified, otherwise they are unqualified.

[0079] Example 1

[0080] (1) Substrate cleaning: Wipe the substrate LED light board with a dust-free cloth dipped in anhydrous ethanol to remove surface stains, and then place it in a drying cabinet for more than 1 hour to remove the moisture adsorbed by the substrate;

[0081] (2) Substrate activation: After drying the cleaned substrate, place it on a rotating rack in a vacuum chamber, evacuate the chamber until the vacuum degree is below 1 Pa, introduce oxygen at a flow rate of 200 sccm, maintain the vacuum degree at 8 Pa, start ICP plasma discharge, and perform plasma bombardment to activate the substrate for 10 minutes at a discharge power of 600 W;

[0082] (3) Coating preparation: evacuate the vacuum chamber to a vacuum degree below 1 Pa, introduce argon at a flow rate of 50 sccm, oxygen at a flow rate of 50 sccm, and octamethylcyclotetrasiloxane (D4) at a flow rate of 250 μL / min, start ICP plasma discharge, the discharge power is 400 W, turn on the bias power supply to load a 450 V bias on the rotating frame, and the deposition time is 10 minutes;

[0083] (4) After the coating is completed, the coated substrate is taken out for thickness test, anti-sulfurization test, calculation of the reduction value of luminous flux after the anti-sulfurization test, and high temperature and high humidity test. The test results are recorded in Table 1.

[0084] Example 2

[0085] Compared with Example 1, other processes remain unchanged, except that: in step (3), the bias voltage loaded on the rotating frame is set to 200 V, and the deposition time is 25 minutes.

[0086] Example 3

[0087] Compared with Example 1, other processes remain unchanged, with the difference being that in step (3), a bias voltage of 200 V is first applied to the turntable, and the deposition time is 20 minutes; then the bias voltage applied to the turntable is changed to 450 V, and the deposition time is 8 minutes.

[0088] Example 4

[0089] Compared with Example 1, other processes remain unchanged, with the difference that in step (3), a bias voltage of 450 V is first applied to the turntable, and the deposition time is 8 minutes; then the bias voltage applied to the turntable is changed to 200 V, and the deposition time is 20 minutes.

[0090] Comparative Example 1

[0091] The uncoated LED light board was subjected to thickness test, anti-sulfurization test, calculation of the reduction value of luminous flux after anti-sulfurization test, and high temperature and high humidity test. The test results are recorded in Table 1.

[0092] Comparative Example 2

[0093] Compared with Example 1, other processes remain unchanged, except that: in step (2), the bias power supply is turned on to load a 400V bias voltage on the rotating frame.

[0094] Comparative Example 3

[0095] Compared with Example 1, other processes remain unchanged, except that in step (3), no bias is applied to the rotating frame, and the deposition time is 40 minutes.

[0096] Comparative Example 4

[0097] Compared with Example 1, other processes remain unchanged, except that the coating time in step 3) is set to 6 minutes.

[0098] Table 1 Test results

[0099]

[0100] According to the test results in Table 1, the coatings prepared in Examples 1 to 3 have excellent light transmittance, anti-sulfurization performance, and environmental aging resistance without affecting the performance of the LED light board itself. In Example 3, the coating includes two film layers formed under different bias voltages in the front and back time periods, and a smaller bias voltage is loaded first, and a larger bias voltage is loaded later. Compared with Examples 1 to 2 and Example 4, it has a better protective effect, and the reduction value of the luminous flux after the anti-sulfurization test is smaller; it may be due to the relatively high carbon atom content in the first formed film layer, the film layer has a lower internal stress, which can transition and buffer the internal stress of the film layer formed in the later time period, making the overall structure of the coating more stable, and the carbon atom content in the film layer formed in the later time period is relatively low, and it has good anti-sulfurization performance.

[0101] It can be seen from Comparative Example 1 that the LED light board without surface coating is very easy to be vulcanized, and after the high temperature and high humidity test, dead light and color deficiency occur.

[0102] It can be seen from Comparative Example 2 that the activation step loads a bias voltage on the rotating frame and improves the ion bombardment capability, but it affects and damages the coating or product, has a significant impact on the luminous flux, and has poor anti-sulfurization effect and poor environmental aging resistance.

[0103] It can be seen from Comparative Example 3 that the rotating frame is not biased during the coating process, resulting in poor anti-sulfurization performance and environmental aging resistance of the prepared coating.

[0104] It can be seen from Comparative Example 4 that the coating thickness formed by reducing the plating time is relatively thin, and the anti-sulfurization effect of the coating is poor.

[0105] The above is only an exemplary embodiment used to illustrate the principle of the present disclosure, and is not intended to limit the scope of protection of the present disclosure. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present disclosure, and these modifications and improvements are also within the scope of protection of the present disclosure.

Claims

1. A method for preparing a coating, characterized in that: include: A support for placing a substrate in a plasma reaction chamber; introducing an activated gas, starting a first plasma discharge, and pre-treating the substrate; The organic silicon monomer is introduced into the plasma reaction chamber, the second plasma discharge is started, and the bracket is biased to deposit a coating with a thickness of 400nm to 2000nm on at least a part of the surface of the substrate.

2. The preparation method according to claim 1, characterized in that: The bias voltage ranges from 100V to 800V.

3. The preparation method according to claim 1, characterized in that: The biasing of the support comprises: The support is loaded with bias pressures of different magnitudes in at least a first time period and a second time period.

4. The preparation method according to claim 3, characterized in that: A bias voltage of 100V to 400V is applied to the bracket during the first time period, and the first time period lasts for 10 minutes to 60 minutes; In the second time period, a bias voltage of 400V to 800V is applied to the bracket, and the duration of the second time period is 5 minutes to 30 minutes.

5. The preparation method according to claim 4, characterized in that: The second time period is located after the first time period.

6. The preparation method according to claim 1, characterized in that: In the process of depositing the coating, the power of the second plasma discharge is 50W to 500W, and the deposition time is 8min to 90min.

7. The preparation method according to claim 1, characterized in that: In the pretreatment, the power of the first plasma discharge is 100W to 600W, and the duration of the first plasma discharge is 5min to 30min.

8. The preparation method according to claim 1, characterized in that: The first plasma discharge and / or the second plasma discharge is an ICP discharge.

9. The preparation method according to claim 1, characterized in that: The first plasma discharge and / or the second plasma discharge is a continuous discharge.

10. The preparation method according to claim 1, characterized in that: The step of introducing the organosilicon monomer into the plasma reaction chamber comprises: The organosilicon monomer and the reaction gas are introduced into the plasma reaction chamber, wherein the reaction gas includes one or more of oxygen, argon, helium and hydrogen, the flow rate of the organosilicon monomer is 10 μL / min to 500 μL / min, and the flow rate of the reaction gas is 50 sccm to 500 sccm.

11. The preparation method according to any one of claims 1 to 10, characterized in that: The thickness of the coating is 400nm-500nm.

12. The preparation method according to any one of claims 1 to 10, characterized in that: The organosilicon monomer comprises at least one of the structures shown in the following formula (1) or (2): In formula (1), R1, R2 and R3 are independently selected from hydrogen atoms, C1-C 12 Substituted or unsubstituted alkyl, C1-C 12 Substituted or unsubstituted alkoxy, or C1-C 12 A substituted or unsubstituted alkylsilyl group, wherein at least one of R1, R2 and R3 is not a hydrogen atom, and R4 is C1-C 12 substituted or unsubstituted alkyl, or C1-C 12 A substituted or unsubstituted alkylsilyl group, X is selected from an oxygen atom, a nitrogen atom or a connecting bond, and n is an integer from 1 to 100; Or (2), R5 and R6 are independently selected from hydrogen atoms, C1-C 12 Substituted or unsubstituted alkyl, C1-C 12 Substituted or unsubstituted alkoxy, or C1-C 12 A substituted or unsubstituted alkylsilyl group, at least one of R5 or R6 is not a hydrogen atom, Y is selected from an oxygen atom or a nitrogen atom, and m is an integer of 3 to 10.

13. The preparation method according to claim 12, characterized in that: The R1, R2 and R3 are independently selected from methyl, ethyl, trimethylsilyl, triethylsilyl or hydrogen atoms, the R4 is methyl, ethyl, trimethylsilyl or triethylsilyl, the X is selected from oxygen or nitrogen, and n is an integer of 1 to 20; The R5 and R6 are independently selected from hydrogen atom, methyl group or ethyl group, and m is an integer of 3-6.

14. The preparation method according to claim 13, characterized in that: The R5 and R6 are selected from methyl groups, the Y is selected from oxygen atoms, and m is an integer of 3-5.

15. The preparation method according to claim 12, characterized in that: The organic silicon monomer includes: one or more of hexamethyldisilazane, hexamethyldisiloxane, polymethylhydrogensiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane.

16. The preparation method according to any one of claims 1 to 10, characterized in that: The substrate includes a light emitting device.

17. The preparation method according to claim 16, characterized in that: The light emitting device comprises an LED substrate, and the LED substrate comprises: an LED lamp, an LED display screen, or an LED bracket.

18. A coating, characterized in that The coating is a plasma polymerization coating of organic silicon, the thickness of the coating is 400nm-2000nm, and after the coating is exposed to 1.3mg / mL sulfur powder and 85°C for 8 hours, the reduction value of the luminous flux of the coating is less than 3%.

19. The coating according to claim 18, characterized in that After the coating is exposed to 1.3 mg / mL sulfur powder and 85° C. for 8 hours, the reduction value of the luminous flux of the coating is less than 2.5%.

20. The coating according to claim 18, characterized in that The thickness of the coating is 400nm-500nm.

21. The coating according to claim 18, characterized in that The coating is prepared by the preparation method according to any one of claims 1 to 17.

22. A device, characterized in that At least a portion of the surface of the device is formed with the coating according to any one of claims 18 to 21.

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