LED module, lamp bead support and color cast detection method of packaging adhesive

Abstract

The invention relates to the technical field of LED modules, and particularly provides a color cast detection method for an LED module, a lamp bead support and packaging glue, and the color cast detection method for the LED module comprises the steps: controlling the number of reflow soldering times and the highest temperature of each reflow soldering based on the target lighting duration of an LED lamp bead; based on the number of reflow soldering times and the highest temperature, a to-be-welded assembly is welded and heated, a to-be-tested LED module in a target state is obtained, and the to-be-welded assembly is obtained by attaching LED lamp beads to a PCB module board; carrying out brightness test on the to-be-tested LED module to obtain the test brightness of the to-be-tested LED module; and comparing the test brightness of the to-be-tested LED module with the standard brightness, and determining a color cast detection result of the to-be-tested LED module. The problem that the detection efficiency and the detection precision cannot be considered at the same time when color cast detection is carried out on an LED module in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of LED modules, and particularly to a method for detecting color deviation of an LED module, a lamp bead bracket and encapsulation glue. Background Art

[0002] The application environment of outdoor display screens is relatively harsh, which requires that the LED modules of outdoor display screens have good heat resistance and yellowing resistance. Especially for outdoor display screens as rental products, most of them are assembled into a whole screen by LED modules with different usage times. The PPA part and the colloid part of the LED modules of such outdoor display screens are prone to color difference, and it is particularly obvious in the black screen state or the blue light state. Therefore, it is necessary to detect the color deviation of the produced LED modules to evaluate the heat resistance and yellowing resistance.

[0003] Related detection methods sample LED lamp beads produced at different time periods, send them to the laboratory after spectroscopy and tape loading, paste the LED lamp beads onto the experimental module board, fix them by reflow soldering, power on the experimental module board to light up the LED lamp beads, and adjust the experimental temperature by controlling the power-on time or using an external heating device, and observe the color difference of the experimental module board. However, the detection efficiency of adjusting the experimental temperature by controlling the power-on time is relatively low. When adjusting the experimental temperature by using an external heating device, the heat on the experimental module board is uneven, and the detection accuracy is relatively low.

[0004] Aiming at the problem that the color deviation detection of LED modules in related technologies cannot take into account both detection efficiency and detection accuracy, no effective solution has been proposed yet. Summary of the Invention

[0005] A method for detecting color deviation of an LED module, a lamp bead bracket and encapsulation glue provided by an embodiment of the present invention at least solves the problem that the color deviation detection of LED modules in related technologies cannot take into account both detection efficiency and detection accuracy.

[0006] In a first aspect, a method for detecting color deviation of an LED module provided by an embodiment of the present invention includes: controlling the number of reflow soldering times and the maximum temperature of each reflow soldering based on the target lighting duration of the LED lamp beads; welding and heating the component to be soldered based on the number of reflow soldering times and the maximum temperature to obtain a to-be-tested LED module in a target state, where the component to be soldered is obtained by pasting the LED lamp beads onto the PCB module board; performing a brightness test on the to-be-tested LED module to obtain the test brightness of the to-be-tested LED module; comparing the test brightness of the to-be-tested LED module with the standard brightness to determine the color deviation detection result of the to-be-tested LED module.

[0007] Furthermore, the color deviation detection method for the LED module provided by the embodiment of the present invention creates a target state of the LED module to be tested by soldering and heating the component to be soldered based on the number of reflow solders and the maximum temperature, including: dividing the area where the component to be soldered passes through the reflow soldering machine into multiple temperature zones, where the temperature in each temperature zone increases from a preset temperature to the maximum temperature and then decreases from the maximum temperature to the preset temperature along the path through which the component to be soldered passes; during each reflow soldering process, passing the component to be soldered through each temperature zone in sequence according to a preset path; and soldering and heating the component to be soldered based on the number of reflow solders and each temperature zone to obtain the LED module to be tested in a target state.

[0008] Furthermore, the color deviation detection method for the LED module provided by the embodiment of the present invention creates a target state of the LED module to be tested by soldering and heating the component to be soldered based on the number of reflow solders and the maximum temperature, including: comparing the test brightness of the LED module to be tested with the standard brightness to determine the color deviation detection result of the LED module to be tested, including: comparing the test brightness of the LED module to be tested with the standard brightness to obtain a brightness test result; performing an aging test on each single LED lamp bead of the LED module to be tested to obtain a lamp bead aging test result; and determining the color deviation detection result of the LED module to be tested based on the brightness test result and the lamp bead aging test result.

[0009] Furthermore, the color deviation detection method for the LED module provided by the embodiment of the present invention creates a target state of the LED module to be tested by soldering and heating the component to be soldered based on the number of reflow solders and the maximum temperature, including: performing an aging test on each single LED lamp bead of the LED module to be tested to obtain a lamp bead aging test result, including: performing an aging test on each single LED lamp bead of the LED module to be tested with red, green, and blue light at a preset aging temperature for a preset aging time to obtain the corresponding red light test brightness, green light test brightness, and blue light test brightness; determining a red light test result based on the red light test brightness and the red light standard brightness; determining a green light test result based on the green light test brightness and the green light standard brightness; determining a blue light test result based on the blue light test brightness and the blue light standard brightness; and determining the lamp bead aging test result of the LED module to be tested based on the red light test result, green light test result, and blue light test result.

[0010] Further, for the color deviation detection method of the LED module provided by the embodiment of the present invention, when the temperature is the preset aging temperature, the single LED lamp bead of the LED module to be tested is subjected to aging tests of red, green, and blue lights according to the preset aging time, and the corresponding red light test brightness, green light test brightness, and blue light test brightness are obtained, including: performing a red light aging test on the first LED lamp bead of the LED module to be tested based on the preset aging temperature, preset aging time, and first aging current to obtain the red light test brightness; performing a green light aging test and a blue light aging test on the second LED lamp bead of the LED module to be tested based on the preset aging temperature, preset aging time, and second aging current to obtain the corresponding green light test brightness and blue light test brightness; wherein, both the first aging current and the second aging current are greater than the standard operating current of the single LED lamp bead of the LED module to be tested.

[0011] Further, for the color deviation detection method of the LED module provided by the embodiment of the present invention, based on the red light test brightness and the red light standard brightness, the red light test result is determined, including: when the red light test brightness is greater than or equal to a preset multiple of the red light standard brightness, the red light test result is that the red light test passes; based on the green light test brightness and the green light standard brightness, the green light test result is determined, including: when the green light test brightness is greater than or equal to a preset multiple of the green light standard brightness, the green light test result is that the green light test passes; based on the blue light test brightness and the blue light standard brightness, the blue light test result is determined, including: when the blue light test brightness is greater than or equal to a preset multiple of the blue light standard brightness, the blue light test result is that the blue light test passes; based on the red light test result, green light test result, and blue light test result, the lamp bead aging test result of the LED module to be tested is determined, including: when the red light test result, green light test result, and blue light test result are all test passed, the lamp bead aging test result of the LED module to be tested is that the aging test passes.

[0012] Further, for the color deviation detection method of the LED module provided by the embodiment of the present invention, the test brightness of the LED module to be tested is compared with the standard brightness to obtain the brightness test result, including: when the test brightness of the LED module to be tested is greater than or equal to a preset multiple of the standard brightness, the brightness test result is that the brightness test passes; based on the brightness test result and the lamp bead aging test result, the color deviation detection result of the LED module to be tested is determined, including: when the brightness test result and the lamp bead aging test result are both test passed, the color deviation detection result of the LED module to be tested is that the color deviation detection passes.

[0013] Second aspect, a method for detecting color deviation of a lamp bead bracket of an LED module provided by an embodiment of the present invention includes: controlling the number of reflow soldering times and the maximum temperature of each reflow soldering based on the target lighting duration of the LED lamp bead; welding and heating a component to be soldered based on the number of reflow soldering times and the maximum temperature to obtain an LED module in a target state, where the component to be soldered is obtained by attaching the LED lamp bead to a PCB module board; performing a whiteness test on the lamp bead bracket to be detected of the LED module to obtain the test whiteness of the lamp bead bracket to be detected; comparing the test whiteness of the lamp bead bracket to be detected with the standard whiteness to determine the color deviation detection result of the lamp bead bracket to be detected.

[0014] Further, for the method for detecting color deviation of a lamp bead bracket of an LED module provided by an embodiment of the present invention, comparing the test whiteness of the lamp bead bracket to be detected with the standard whiteness to determine the color deviation detection result of the lamp bead bracket to be detected includes: comparing the test whiteness of the lamp bead bracket to be detected with the standard whiteness to obtain a whiteness test result; determining the color deviation detection result of the lamp bead bracket to be detected based on the whiteness test result; or, performing an aging test on a single LED lamp bead of the LED module to obtain a lamp bead aging test result; determining the color deviation detection result of the lamp bead bracket to be detected based on the whiteness test result and the lamp bead aging test result.

[0015] Third aspect, a method for detecting color deviation of a packaging glue of an LED module provided by an embodiment of the present invention includes: controlling the number of reflow soldering times and the maximum temperature of each reflow soldering based on the target lighting duration of the LED lamp bead; heating a glue cake based on the number of reflow soldering times and the maximum temperature to obtain a glue cake to be detected in a target state, where the glue cake is a glue cake obtained by processing the packaging glue to be detected of the LED module; performing a whiteness test on the glue cake to be detected to obtain the test whiteness of the glue cake to be detected; comparing the test whiteness of the glue cake to be detected with the standard whiteness to determine the color deviation detection result of the packaging glue to be detected.

[0016] A method for detecting color deviation of an LED module, a lamp bead bracket and a packaging glue provided by an embodiment of the present invention controls the number of reflow soldering times and the maximum temperature of each reflow soldering based on the target lighting duration of the LED lamp bead; welds and heats a component to be soldered based on the number of reflow soldering times and the maximum temperature to obtain a to-be-detected LED module in a target state, and can simulate the state of the LED lamp bead under different lighting durations through the number of reflow soldering times and the temperature, so as to quickly detect whether the LED module in the corresponding state is color deviated and the degree of color deviation, and has the advantages of high detection efficiency and high detection accuracy, and can solve the problem that it is impossible to take into account both detection efficiency and detection accuracy in detecting color deviation of an LED module in the related art. Description of the Drawings

[0017] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other embodiments can be obtained based on these drawings.

[0018] Figure 1 It is a flowchart of the steps of a method for detecting color deviation of an LED module in an embodiment of the present invention.

[0019] Figure 2 It is a flowchart of the steps of a method for detecting color deviation of a lamp bead bracket of an LED module in an embodiment of the present invention.

[0020] Figure 3 It is a flowchart of the steps of a method for detecting color deviation of encapsulation glue of an LED module in an embodiment of the present invention. Detailed implementation manners

[0021] The following will describe the embodiments of the present invention in more detail with reference to the drawings. Although some embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not used to limit the protection scope of the present invention.

[0022] The LED modules of outdoor displays need to have good heat resistance and yellowing resistance to face harsh application environments. Especially for outdoor displays as rental products, most of them are assembled into a whole screen by LED modules with different usage times. The PPA part and the colloid part of the LED modules of such outdoor displays are prone to color difference, and it is particularly obvious in the black screen state or the blue light state. Therefore, it is necessary to detect the color deviation of the produced LED modules to evaluate the heat resistance and yellowing resistance.

[0023] Related detection methods sample LED lamp beads produced at different times, send them to the laboratory after spectroscopy and banding, paste the LED lamp beads on the experimental module board, fix them by reflow soldering, power on the experimental module board to light up the LED lamp beads, and adjust the experimental temperature by controlling the power-on time or using an external heating device, and observe the color difference of the experimental module board. However, the detection efficiency of adjusting the experimental temperature by controlling the power-on time is relatively low. When adjusting the experimental temperature by using an external heating device, the heat on the experimental module board is uneven, and the detection accuracy is relatively low.

[0024] Therefore, please refer to Figure 1As shown in the figure, an embodiment of the present invention provides a method for detecting color deviation of an LED module, including steps S101 to S104.

[0025] Step S101, based on the target lighting duration of the LED lamp beads, control the number of reflow soldering times and the maximum temperature of each reflow soldering.

[0026] Step S102, based on the number of reflow soldering times and the maximum temperature, solder and heat the component to be soldered to obtain the LED module to be tested in the target state, where the component to be soldered is obtained by attaching the LED lamp beads to the PCB module board.

[0027] Step S103, perform a brightness test on the LED module to be tested to obtain the test brightness of the LED module to be tested.

[0028] Step S104, compare the test brightness of the LED module to be tested with the standard brightness to determine the color deviation detection result of the LED module to be tested.

[0029] It can be understood that for an outdoor display screen assembled by LED modules with different usage times, the lighting durations of the LED lamp beads of each LED module are different.

[0030] In this embodiment, the state of the LED lamp beads under different lighting durations is simulated by the number of reflow soldering times and temperature. The reflow soldering operation used for welding and fixing in the related technology is improved to an operation that combines welding and fixing with temperature variable control, which can significantly improve the detection efficiency.

[0031] Specifically, the components of the LED lamp beads include but are not limited to LED chips, lamp bead brackets, and encapsulation glue.

[0032] The lamp bead brackets include but are not limited to brackets made of polyphthalamide (PPA).

[0033] In the related technology, the LED lamp beads obtained through die bonding, wire bonding, spot inspection, appearance inspection, spectral analysis, and tape feeding operations are only subjected to one reflow soldering to fix the above LED lamp beads to the PCB module board to obtain the module to be tested. By controlling the power-on time of the module to be tested or adjusting the detection temperature using an external heating device to reflect the state of the above LED lamp beads under different lighting durations, the detection efficiency is low.

[0034] In this embodiment, the state of the LED lamp beads under different lighting durations is simulated by controlling the number of reflow soldering times and temperature. For example, the number of reflow soldering times is 1-5, and the maximum temperature of each reflow soldering is 200°C - 280°C. It helps to quickly detect whether the LED module in the corresponding state is color deviated and the degree of color deviation.

[0035] In addition, for the LED module under test that does not have color deviation at the target lighting duration, those skilled in the art can also start from the number of reflow soldering times and temperature corresponding to the target lighting duration and continue to increase the number of reflow soldering times and temperature until the color deviation detection result of the LED module under test fails the detection.

[0036] Based on the number of reflow soldering times and temperature corresponding to the case where the detection fails, the color deviation lighting duration of the LED module under test can be determined. Among them, when the lighting duration of the LED beads in the LED module under test is less than the color deviation lighting duration, the above-mentioned LED module under test does not have color deviation; when the lighting duration of the LED beads in the LED module under test is greater than or equal to the color deviation lighting duration, the above-mentioned LED module under test has color deviation or is prone to color deviation.

[0037] In addition, the component to be soldered is obtained by attaching LED beads to the PCB module board, which means placing the LED beads at the corresponding pad positions on the PCB module board and connecting the LED beads to the pads of the PCB module board through soldering materials such as solder paste. Obviously, the stability of this connection is relatively low and needs to be fixed by reflow soldering.

[0038] In addition, for the method of performing a brightness test on the LED module under test and comparing the test brightness of the LED module under test with the standard brightness, it includes but is not limited to: using a light gun (also known as a luminance meter or a photometer) to test the brightness value of the LED module under test and comparing the brightness value of the LED module under test after a preset brightness duration with the standard brightness value. Among them, the standard brightness value can be determined by those skilled in the art according to empirical values and actual situations, can be obtained by querying a standard database or a standard data table, or can be the initial brightness value after the LED module under test is powered on.

[0039] Or, on the same PCB module board, power on the beads of the LED module under test and the standard beads and compare the light emission differences.

[0040] It can be understood that whether the LED module has color deviation and the degree of color deviation are related to the heat resistance and yellowing resistance of the bead bracket and the encapsulation glue. If the heat resistance and yellowing resistance of the bead bracket and the encapsulation glue are better, the LED module is not easily colored, and even if it is colored, it is colored to a relatively low degree. This embodiment also gives a method for detecting color deviation of the bead bracket and the encapsulation glue, which helps those skilled in the art to determine the source of color deviation and compare to obtain bead brackets and encapsulation glues that are not easily colored, which will be specifically introduced later.

[0041] In summary, a method for detecting color deviation of an LED module provided by an embodiment of the present invention controls the number of reflows and the maximum temperature of each reflow based on the target lighting duration of the LED beads; welds and heats the component to be welded based on the number of reflows and the maximum temperature to obtain the LED module to be tested in the target state. It can simulate the state of the LED beads under different lighting durations through the number of reflows and temperature, so as to quickly detect whether the LED module in the corresponding state is color deviated and the degree of color deviation. It has the advantages of high detection efficiency and high detection accuracy, and can solve the problem that the detection efficiency and detection accuracy cannot be taken into account when detecting the color deviation of the LED module in the related art.

[0042] Preferably, in step S102, welding and heating the component to be welded based on the number of reflows and the maximum temperature to obtain the LED module to be tested in the target state includes steps S1021 to S1023.

[0043] In step S1021, the area of the component to be welded passing through the reflow soldering machine is divided into multiple temperature zones. Among them, the temperature in each temperature zone increases from a preset temperature to the maximum temperature and then decreases from the maximum temperature to the preset temperature according to the path passed by the component to be welded.

[0044] For example, the area of the component to be welded passing through the reflow soldering machine is divided into 10 temperature zones, and the temperature in each temperature zone gradually increases from 130 °C to 250 °C and then gradually decreases from 250 °C to 130 °C.

[0045] The change rate of temperature increase and temperature decrease can be determined according to the speed or time of the component to be welded passing through each temperature zone, which belongs to the prior art and will not be elaborated here in this embodiment.

[0046] In step S1022, during each reflow, the component to be welded is passed through each temperature zone in sequence according to a preset path.

[0047] It can be understood that the component to be welded is placed in a fixture. Among them, the fixture has a positioning structure matching the PCB module board of the component to be welded.

[0048] The fixture is placed on a conveyor belt. Among them, the width of the conveyor belt can be adjusted according to the width of the fixture or the width of the PCB module board of the component to be welded.

[0049] The conveyor belt is installed inside the reflow soldering machine and runs through each temperature zone of the reflow soldering machine.

[0050] Therefore, the above preset path can be the movement path of the conveyor belt.

[0051] In step S1023, welding and heating the component to be welded based on the number of reflows and each temperature zone to obtain the LED module to be tested in the target state.

[0052] The greater the number of reflow soldering times or the higher the maximum temperature in each temperature zone, the longer the lighting duration of the LED lamp beads of the LED module to be tested, that is, the longer the service life of the LED module to be tested.

[0053] It can be understood that through the above steps S1021 to S1023, the accuracy of temperature variable control can be improved, the LED module to be tested can be heated evenly, and the state of the LED module to be tested under the corresponding service life can be simulated more accurately.

[0054] Preferably, in step S104, comparing the test brightness of the LED module to be tested with the standard brightness to determine the color deviation detection result of the LED module to be tested, including: Method 1: Comparing the test brightness of the LED module to be tested with the standard brightness to obtain a brightness test result. Based on the brightness test result, determine the color deviation detection result of the LED module to be tested.

[0055] Method 2: Aging test is performed on a single LED lamp bead of the LED module to be tested to obtain a lamp bead aging test result. Based on the brightness test result and the lamp bead aging test result, determine the color deviation detection result of the LED module to be tested.

[0056] It can be understood that determining the color deviation detection result of the LED module to be tested based on the brightness test result has a high detection efficiency. Determining the color deviation detection result of the LED module to be tested based on the brightness test result and the lamp bead aging test result has a higher detection accuracy.

[0057] Preferably, in Method 1, comparing the test brightness of the LED module to be tested with the standard brightness to obtain a brightness test result, including: when the test brightness of the LED module to be tested is greater than or equal to a preset multiple of the standard brightness, the brightness test result is that the brightness test passes.

[0058] For example, when the test brightness of the LED module to be tested is greater than or equal to 0.95 times the standard brightness, the brightness test result is that the brightness test passes.

[0059] It can be understood that the test brightness of the LED module to be tested is the initial brightness measured when the LED module to be tested is powered on and emits light, without waiting for a certain power-on time to measure. This is one of the advantages of the above method provided by this embodiment compared with the related art. There is no need to control the power-on time of the LED module to be tested, which helps to achieve rapid color deviation detection.

[0060] The above standard brightness is the brightness after the LED module prepared with a known PPA bracket and encapsulation glue that is not prone to color deviation and only undergoes one reflow soldering is powered on.

[0061] It can be understood that for Method 1, when the brightness test result is that the brightness test passes, the color deviation detection result of the LED module to be tested is that the color deviation detection passes, and the color deviation detection of the LED module to be tested can be quickly realized.

[0062] Exemplarily, this embodiment also provides the experimental data of the above Method 1 to verify the beneficial effects of the above color deviation detection method, which are specifically as follows: The standard brightness is 4000, which is from a standard LED module that has undergone 1 reflow soldering. Among them, the above standard LED module uses a PPA bracket and encapsulant with a whiteness of 70, and LED lamp beads with RGB brightnesses of 500 / 780 / 110 in sequence. Define the above standard LED module as not having color deviation. When the test brightness of the LED module to be tested is greater than or equal to 0.95 times the standard brightness, the brightness test result of the LED module to be tested is that the brightness test passes, and the LED module to be tested is not prone to color deviation.

[0063] The LED module to be tested is respectively subjected to 2 / 3 / 4 / 5 reflow soldering operations. Each reflow soldering passes through 10 temperature zones, and the maximum temperature is set to 250 °C. The test results are shown in the following table.

[0064] Table 1 Test brightness of the LED module to be tested

[0065] When the test brightness is less than 0.95 times (3800) of the standard brightness of 4000, that is, when the difference between the test brightness and the standard brightness is within -5%, the LED module to be tested is not prone to color deviation. The greater the absolute value of the difference from the standard brightness, the higher the degree of color deviation of the LED module to be tested.

[0066] It can be seen that when the number of reflow soldering operations is less than 3, the LED module to be tested is not prone to color deviation, and the usage duration of the LED module to be tested (the lighting duration of the LED lamp beads) should not exceed the color deviation lighting duration corresponding to 3 reflow soldering operations.

[0067] Therefore, when actually detecting the above LED module to be tested, when the number of reflow soldering operations is controlled to be 2 based on the target lighting duration of the LED lamp beads, the final color deviation detection result is that the detection passes, and the above LED module to be tested is not prone to color deviation. When the number of reflow soldering operations is controlled to be 3 based on the target lighting duration of the LED lamp beads, the final color deviation detection result is that the detection fails, and the above LED module to be tested is prone to color deviation.

[0068] In other words, based on the above color deviation detection method provided by this embodiment, the state of the LED lamp beads at different lighting durations can be simulated through the number of reflow soldering operations and temperature, so as to quickly detect whether the LED module in the corresponding state has color deviation and the degree of color deviation.

[0069] It can be understood that the above experimental verification was carried out by keeping the maximum temperature of the reflow soldering constant and using the number of reflow soldering times as a variable.

[0070] It is also possible to perform the same number of reflow soldering operations on multiple LED modules to be tested prepared from the same material, but the maximum temperature of the reflow soldering for each LED module to be tested is different. Verification is carried out by comparing the appearance differences and brightness differences of each LED module to be tested after being powered on.

[0071] For example, the maximum temperature of the reflow soldering machine is set to 200°C / 220°C / 240°C / 260°C / 280°C respectively, and the appearance differences of the LED module boards to be tested at different maximum temperatures are observed. At the same time, a light gun is used to measure the brightness of the LED module boards to be tested. Taking the brightness of the LED module board at 200°C as the standard brightness, and the brightness of the LED module boards to be tested at other maximum temperatures as the test brightness. When the test brightness is less than 0.95 times the standard brightness, the corresponding LED module to be tested fails the color deviation detection and is prone to color deviation.

[0072] Among them, when observing the appearance differences of the LED module boards to be tested at different maximum temperatures, the LED module boards to be tested at different maximum temperatures can be arranged in sequence along a preset direction for convenient observation.

[0073] Preferably, in the second method, an aging test is performed on a single LED lamp bead of the LED module to be tested to obtain the lamp bead aging test results, including: at a temperature of the preset aging temperature, according to the preset aging time, an aging test of red, green, and blue lights is performed on a single LED lamp bead of the LED module to be tested to obtain the corresponding red light test brightness, green light test brightness, and blue light test brightness.

[0074] Based on the red light test brightness and the red light standard brightness, the red light test result is determined.

[0075] Based on the green light test brightness and the green light standard brightness, the green light test result is determined.

[0076] Based on the blue light test brightness and the blue light standard brightness, the blue light test result is determined.

[0077] Based on the red light test result, the green light test result, and the blue light test result, the lamp bead aging test result of the LED module to be tested is determined.

[0078] It can be understood that an LED module prepared from LED lamp beads that are prone to aging is prone to color deviation. An LED lamp bead that fails the aging test is an LED lamp bead that is prone to aging.

[0079] The number of LED beads in the LED module to be tested is multiple. Aging testing a single LED bead of the LED module to be tested means that the object form of the aging test is a single LED bead, that is, there is no need to conduct an aging test on the entire LED module to be tested. At the same time, it is not limited to only testing one LED bead.

[0080] In addition, compared with the aging test without color distinction, conducting the aging test of red, green, and blue three-color light can accurately understand the performance of the LED bead under the corresponding color channels and meet the requirements of outdoor displays for color accuracy and color consistency.

[0081] Furthermore, under the condition that the temperature is the preset aging temperature, according to the preset aging time, conduct the aging test of red, green, and blue three-color light on a single LED bead of the LED module to be tested, and obtain the corresponding red light test brightness, green light test brightness, and blue light test brightness, including: based on the preset aging temperature, preset aging time, and the first aging current, conduct a red light aging test on the first LED bead of the LED module to be tested to obtain the red light test brightness.

[0082] Based on the preset aging temperature, preset aging time, and the second aging current, conduct a green light aging test and a blue light aging test on the second LED bead of the LED module to be tested to obtain the corresponding green light test brightness and blue light test brightness.

[0083] Among them, both the first aging current and the second aging current are greater than the standard operating current of a single LED bead of the LED module to be tested.

[0084] It can be understood that those skilled in the art can determine the specific values of the preset aging temperature and preset aging time according to experience values and actual situations. For example, the preset aging temperature is 85 °C, and the preset aging time is 168H.

[0085] According to the magnitude of the standard operating current or the conventional operating current of a single LED bead, those skilled in the art need to adjust the magnitudes of the first aging current and the second aging current accordingly. For example, the standard operating current of a single LED bead is 10 mA, the first aging current is 25 mA, and the second aging current is 15 mA.

[0086] It can be understood that both the first aging current and the second aging current are greater than the standard operating current, which can accelerate the aging of the above-mentioned LED beads and improve the detection efficiency.

[0087] Based on the red light test brightness and the red light standard brightness, determine the red light test result, including: when the red light test brightness is greater than or equal to a preset multiple of the red light standard brightness, the red light test result is that the red light test passes.

[0088] Based on the green light test brightness and the green light standard brightness, determine the green light test result, including: when the green light test brightness is greater than or equal to a preset multiple of the green light standard brightness, the green light test result is that the green light test passes.

[0089] Based on the blue light test brightness and the blue light standard brightness, determine the blue light test result, including: when the blue light test brightness is greater than or equal to a preset multiple of the blue light standard brightness, the blue light test result is that the blue light test passes.

[0090] It can be understood that the above preset multiple can be determined by those skilled in the art according to empirical values and actual situations. For example, the above preset multiple is 0.7 or 0.75.

[0091] The red light standard brightness can be obtained by querying a standard database or a standard data table, or can be the initial brightness of the first LED lamp bead under the first aging current.

[0092] The green light standard brightness and the blue light standard brightness can be obtained by querying a standard database or a standard data table, or can be the initial brightness of the second LED lamp bead under the second aging current.

[0093] Exemplarily, the operations for performing a high-temperature aging test on a single LED lamp bead of the LED module to be tested include: placing an aging rack in an incubator with a temperature set at 85°C, placing the first LED lamp bead from the LED module to be tested on the above aging rack, setting the current of the aging rack to 25 mA to light up the first LED lamp bead, and measuring the initial red light brightness of the first LED lamp bead; after the first LED lamp bead is lit for 168H, measuring the red light test brightness of the first LED lamp bead.

[0094] Placing the second LED lamp bead from the same LED module to be tested on the aging rack, setting the current of the aging rack to 15 mA to light up the second LED lamp bead, and measuring the initial green light brightness and the initial blue light brightness of the second LED lamp bead; after the second LED lamp bead is lit for 168H, measuring the green light test brightness and the blue light test brightness of the second LED lamp bead.

[0095] Further, based on the red light test result, the green light test result, and the blue light test result, determine the lamp bead aging test result of the LED module to be tested, including: when the red light test result, the green light test result, and the blue light test result are all test passed, the lamp bead aging test result of the LED module to be tested is that the aging test passes.

[0096] Continuing the above example, when the red light test brightness of the first LED lamp bead is less than 0.7 times the initial red light brightness, the red light test of the first LED lamp bead passes.

[0097] When the measured brightness of the green light of the second LED lamp bead is less than 0.7 times the initial brightness of the green light, the green light test of the second LED lamp bead passes.

[0098] When the measured brightness of the blue light of the second LED lamp bead is less than 0.7 times the initial brightness of the blue light, the blue light test of the second LED lamp bead passes.

[0099] When the red light test of the first LED lamp bead passes, and the green light test and blue light test of the second LED lamp bead both pass, the bead aging test of the above-mentioned LED module to be tested passes.

[0100] It can be understood that for Method 2, when both the brightness test result and the bead aging test result are test passed, the color deviation detection result of the LED module to be tested is that the color deviation detection passes, which can improve the accuracy of the color deviation detection of the LED module to be tested.

[0101] For the experimental verification of the color deviation detection of the LED module to be tested based on Method 2, reference can be made to the experimental verification of the color deviation detection of the lamp bead bracket and encapsulation glue in the follow-up. This embodiment will not be elaborated here.

[0102] Please refer to Figure 2 As shown, the embodiment of the present invention also provides a method for detecting color deviation of a lamp bead bracket of an LED module, including steps S201 to S204.

[0103] Step S201, based on the target lighting duration of the LED lamp bead, control the number of reflow soldering times and the maximum temperature of each reflow soldering.

[0104] Step S202, based on the number of reflow soldering times and the maximum temperature, weld and heat the components to be soldered to obtain an LED module in a target state, where the components to be soldered are obtained by attaching the LED lamp beads to the PCB module board.

[0105] Step S203, perform a whiteness test on the lamp bead bracket to be tested of the LED module to obtain the test whiteness of the lamp bead bracket to be tested.

[0106] Step S204, compare the test whiteness of the lamp bead bracket to be tested with the standard whiteness to determine the color deviation detection result of the lamp bead bracket to be tested.

[0107] It can be understood that a whiteness tester is used to test the test whiteness of the lamp bead bracket to be tested.

[0108] The standard whiteness can be determined by those skilled in the art according to experience values and actual situations, can be obtained by querying a standard database or standard data table, or can be the initial whiteness of the lamp bead bracket to be tested before reflow soldering.

[0109] It can be understood that when the heat resistance and yellowing resistance of the light bead bracket to be tested are poor and it is prone to color deviation, the LED module prepared from the above-mentioned light bead bracket to be tested will be prone to color deviation.

[0110] The method for detecting color deviation of the light bead bracket of the LED module provided in the embodiment of the present invention controls the number of reflow soldering and the maximum temperature of each reflow soldering based on the target lighting duration of the LED light bead; based on the number of reflow soldering and the maximum temperature, the component to be soldered is welded and heated to obtain the LED module to be tested in the target state, and can simulate the state of the LED light bead under different lighting durations through the number of reflow soldering and temperature, so as to quickly detect whether the light bead bracket of the LED module in the corresponding state is color deviated and the degree of color deviation, having the advantages of high detection efficiency and high detection accuracy.

[0111] Preferably, in step S204, comparing the test whiteness of the light bead bracket to be tested with the standard whiteness to determine the color deviation detection result of the light bead bracket to be tested includes: comparing the test whiteness of the light bead bracket to be tested with the standard whiteness to obtain the whiteness test result. Determining the color deviation detection result of the light bead bracket to be tested based on the whiteness test result.

[0112] Or, aging test is performed on a single LED light bead of the LED module to obtain the light bead aging test result. Determining the color deviation detection result of the light bead bracket to be tested based on the above whiteness test result and the light bead aging test result.

[0113] Further, comparing the test whiteness of the light bead bracket to be tested with the standard whiteness to obtain the whiteness test result includes: when the difference between the test whiteness of the light bead bracket to be tested and the standard whiteness is within the preset range, the whiteness test result of the light bead bracket to be tested is that the whiteness test passes.

[0114] It can be understood that the above preset range can be determined by those skilled in the art according to prior values and actual situations.

[0115] For example, the standard whiteness is the initial whiteness X of the light bead bracket to be tested without reflow soldering. When the test whiteness of the light bead bracket to be tested is X±5, the yellowing degree of the light bead bracket to be tested is low and the heat resistance is good, and this light bead bracket to be tested is not prone to color deviation.

[0116] Exemplarily, the present embodiment also provides an experimental verification of the above solution, which is specifically as follows: The standard whiteness of the PPA bracket is 70, and the standard RGB brightness of the LED light bead is 500 / 780 / 110 in sequence.

[0117] According to the PPA bracket A, through a series of operations including die bonding, wire bonding, inspection, appearance inspection, spectroscopy, and waiting for the tape, the corresponding LED lamp bead A is prepared. The LED lamp bead A is laid flat in the fixture and subjected to 3 times of reflow soldering through the reflow soldering machine. Then, the test whiteness of the PPA bracket A is measured using a whiteness tester, and the LED lamp bead A is subjected to high-temperature aging test according to the above method of three-color light aging test to obtain the test brightness of the LED lamp bead A.

[0118] The same operations are performed on the PPA bracket B to obtain the test whiteness of the PPA bracket B and the test brightness of the corresponding LED lamp bead B of the PPA bracket B.

[0119] Among them, the encapsulation glue used for the LED lamp bead A and the LED lamp bead B is the same. Compared with the PPA bracket B, titanium dioxide (TiO 2 ) is configured in the composition of the PPA bracket A.

[0120] Each reflow soldering passes through 10 temperature zones, and the maximum temperature is set to 250 °C. The color deviation detection data is shown in the following table.

[0121] Table 2 Color deviation detection data of bracket A and bracket B

[0122] When the difference between the test whiteness of the PPA bracket and the standard whiteness of 70 is less than ±5, the heat resistance and yellowing resistance of the PPA bracket are better and it is not easy to have color deviation. The greater the absolute value of the difference from the standard whiteness, the higher the degree of color deviation of the PPA bracket.

[0123] When the RGB test brightness of the LED lamp bead is less than 0.7 times of the standard brightness of 500 / 780 / 110, that is, when the difference between the RGB test brightness of the LED lamp bead and the standard brightness is within -30%, the LED lamp bead is not easy to age.

[0124] It can be seen that compared with the PPA bracket B, the PPA bracket A has better heat resistance and yellowing resistance and is not easy to have color deviation. Compared with the LED lamp bead B prepared from the PPA bracket B, the LED lamp bead A prepared from the PPA bracket A is not easy to age, and the LED module prepared from the LED lamp bead A is not easy to have color deviation.

[0125] In other words, based on the color deviation detection method of the lamp bead bracket of the above LED module provided in this embodiment, the state of the LED lamp bead under different lighting durations can be simulated through the number of reflow soldering times and temperature, so as to quickly detect whether the lamp bead bracket of the LED module in the corresponding state has color deviation and the degree of color deviation.

[0126] Please refer to Figure 3As shown in the figure, the embodiment of the present invention also provides a method for detecting color deviation of the encapsulation glue of an LED module, including steps S301 to S304.

[0127] Step S301: Based on the target lighting duration of the LED lamp beads, control the number of reflow soldering times and the maximum temperature of each reflow soldering.

[0128] Step S302: Based on the number of reflow soldering times and the maximum temperature, heat the glue cake to obtain a glue cake to be tested in a target state, where the glue cake is obtained by processing the encapsulation glue to be tested of the LED module.

[0129] Step S303: Conduct a whiteness test on the glue cake to be tested to obtain the test whiteness of the glue cake to be tested.

[0130] Step S304: Compare the test whiteness of the glue cake to be tested with the standard whiteness to determine the color deviation detection result of the encapsulation glue to be tested.

[0131] It can be understood that the target state of the glue cake to be tested refers to the state of the encapsulation glue to be tested that is a component of the above-mentioned LED lamp beads after the LED lamp beads have been lit for the target lighting duration. Among them, processing the encapsulation glue to be tested into the form of a glue cake will not affect the above-mentioned target state, and processing the encapsulation glue to be tested into the form of a glue cake is for the convenience of heating and testing.

[0132] It can be understood that the test whiteness of the glue cake to be tested is measured using a whiteness tester. Among them, the test whiteness of the glue cake to be tested is the test whiteness of the encapsulation glue to be tested.

[0133] The standard whiteness can be determined by those skilled in the art according to empirical values and actual situations, can be obtained by querying a standard database or a standard data table, or can be the initial whiteness of the glue cake to be tested before reflow soldering.

[0134] It can be understood that in the case where the heat resistance and yellowing resistance of the encapsulation glue to be tested are poor and it is prone to color deviation, the LED module prepared from the above-mentioned encapsulation glue to be tested will be prone to color deviation.

[0135] The above method for detecting color deviation of the encapsulation glue of the LED module provided by the embodiment of the present invention controls the number of reflow soldering times and the maximum temperature of each reflow soldering based on the target lighting duration of the LED lamp beads; based on the number of reflow soldering times and the maximum temperature, heats the glue cake to obtain a glue cake to be tested in a target state, and can simulate the state of the LED lamp beads under different lighting durations through the number of reflow soldering times and temperature, so as to quickly detect whether the encapsulation glue is color deviated and the degree of color deviation in the corresponding state, and has the advantages of high detection efficiency and high detection accuracy.

[0136] Preferably, in step S304, comparing the measured whiteness of the to-be-tested glue cake with the standard whiteness to determine the color deviation detection result of the to-be-tested encapsulation glue includes: comparing the measured whiteness of the to-be-tested glue cake with the standard whiteness to obtain the whiteness test result. Determining the color deviation detection result of the to-be-tested glue cake based on the whiteness test result.

[0137] Alternatively, aging tests are performed on single LED beads of the LED module to obtain the bead aging test results. Based on the above whiteness test results and the bead aging test results, the color deviation detection result of the to-be-tested glue cake is determined. Wherein, the above LED module is an LED module prepared from the to-be-tested encapsulation glue.

[0138] Further, comparing the measured whiteness of the to-be-tested glue cake with the standard whiteness to obtain the whiteness test result includes: when the difference between the measured whiteness of the to-be-tested glue cake and the standard whiteness is within a preset range, the whiteness test result of the to-be-tested glue cake is that the whiteness test passes.

[0139] It can be understood that the above preset range can be determined by those skilled in the art according to prior values and actual situations.

[0140] For example, the standard whiteness is the initial whiteness Y of the to-be-tested glue cake without reflow soldering. When the measured whiteness of the to-be-tested glue cake is Y±5, the corresponding yellowing degree of the to-be-tested encapsulation glue is low and the heat resistance is good, and this to-be-tested encapsulation glue is not easily color deviated.

[0141] Exemplarily, this embodiment also provides an experimental verification of the above solution, which is specifically as follows: the standard whiteness of the encapsulation glue is 70, and the standard RGB brightness of the LED beads is 500 / 780 / 110 in sequence.

[0142] Mix and stir encapsulation glue C according to the ratio of encapsulation glue C1: encapsulation glue C2: diffusion powder: matte powder = 1:1:0.1:0.3. After degassing by a degassing machine, pour it into a glue cake jig, and perform multi-stage baking at 90°C - 100°C / 1H + 130°C - 140°C / 3.5H to make a glue cake with a diameter of 3 cm and a thickness of 0.5 cm. After 3 times of reflow soldering through a reflow soldering machine, use a whiteness tester to measure the measured whiteness of encapsulation glue C, and perform high-temperature aging tests on LED beads C prepared from encapsulation glue C according to the above method of three-color light aging tests to obtain the measured brightness of LED beads C. Wherein, encapsulation glue C1 is epoxy resin and encapsulation glue C2 is antioxidant.

[0143] Perform the same operations on encapsulation glue D to obtain the measured whiteness of encapsulation glue D and the measured brightness of LED beads D corresponding to encapsulation glue D. Wherein, the ratio of encapsulation glue D is encapsulation glue D1: encapsulation glue D2: diffusion powder: matte powder = 1:1:0.1:0.3, encapsulation glue D1 is epoxy resin, and encapsulation glue D2 is curing agent.

[0144] Among them, the PPA brackets used for LED lamp bead C and LED lamp bead D are the same.

[0145] Each reflow soldering process passes through 10 temperature zones, and the maximum temperature is set at 250 °C. The color deviation detection data is shown in the following table.

[0146] Table 3 Color deviation detection data of encapsulant C and encapsulant D

[0147] When the difference between the measured whiteness of the encapsulant and the standard whiteness of 70 is less than ±5, the heat resistance and yellowing resistance of the encapsulant are better and it is not easy to have color deviation. The greater the absolute value of the difference from the standard whiteness, the higher the degree of color deviation of the encapsulant.

[0148] When the RGB test brightness of the LED lamp bead is less than 0.7 times the standard brightness of 500 / 780 / 110, that is, when the difference between the RGB test brightness of the LED lamp bead and the standard brightness is within -30%, the LED lamp bead is not easy to age.

[0149] It can be seen that compared with encapsulant D, encapsulant C has better heat resistance and yellowing resistance and is not easy to have color deviation. Compared with LED lamp bead D prepared from encapsulant D, LED lamp bead C prepared from encapsulant C is not easy to age, and the LED module prepared from LED lamp bead C is not easy to have color deviation.

[0150] In other words, based on the above color deviation detection method of the encapsulant of the LED module provided in this embodiment, the state of the LED lamp bead under different lighting durations can be simulated through the number of reflow soldering times and temperature, so as to quickly detect whether the encapsulant has color deviation and the degree of color deviation under the corresponding state, which has the advantages of high detection efficiency and high detection accuracy.

[0151] It should be noted that the term "including" and its variants used in the embodiments of the present invention are open-ended, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless otherwise clearly specified in the context, it should be understood as "one or more". The descriptions of terms such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features.

[0152] In the method embodiments provided by the embodiments of the present invention, the steps recorded can be executed in different orders and / or executed in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The protection scope of the present invention is not limited in this regard.

[0153] The term "embodiment" in this specification means that the specific features, structures or characteristics described in connection with the embodiments may be included in at least one embodiment of the present invention. The phrase appears in various positions in the specification does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. The embodiments in this specification are all described in a related manner, and the same or similar parts among the embodiments are referred to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiments.

[0154] The above-described embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation of the protection scope. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A method for detecting color cast of an LED module, characterized in that: include: Based on the target lighting duration of the LED lamp beads, control the number of reflow soldering and the maximum temperature of each reflow soldering; Based on the number of reflow soldering times and the maximum temperature, the assembly to be soldered is soldered and heated to obtain a LED module to be tested in a target state, wherein the assembly to be soldered is obtained by attaching the LED lamp bead to a PCB module board; Performing a brightness test on the LED module to be tested to obtain a test brightness of the LED module to be tested; The test brightness of the LED module to be tested is compared with the standard brightness to determine the color cast detection result of the LED module to be tested.

2. The method according to claim 1, characterized in that: Based on the number of reflow soldering times and the maximum temperature, soldering and heating are performed on the assembly to be soldered to obtain an LED module to be tested in a target state, including: Divide the area where the component to be soldered passes through the reflow soldering machine into multiple temperature zones, wherein the temperature in each temperature zone increases from a preset temperature to the maximum temperature and then decreases from the maximum temperature to the preset temperature according to the path through which the component to be soldered passes; During each reflow process, the component to be soldered passes through each temperature zone in sequence according to a preset path; Based on the number of reflow soldering times and the various temperature zones, the components to be soldered are soldered and heated to obtain a LED module to be tested in a target state.

3. The method according to claim 1, characterized in that Comparing the test brightness of the LED module to be tested with the standard brightness to determine the color cast detection result of the LED module to be tested, including: Comparing the test brightness of the LED module to be tested with the standard brightness to obtain a brightness test result; Performing an aging test on a single LED lamp bead of the LED module to be tested to obtain a lamp bead aging test result; Based on the brightness test result and the lamp bead aging test result, a color cast detection result of the LED module to be tested is determined.

4. The method according to claim 3, characterized in that Performing an aging test on a single LED lamp bead of the LED module to be tested to obtain a lamp bead aging test result, including: When the temperature is the preset aging temperature, a single LED lamp bead of the LED module to be tested is subjected to an aging test of red, green and blue light according to the preset aging time to obtain corresponding red light test brightness, green light test brightness and blue light test brightness; Determine a red light test result based on the red light test brightness and the red light standard brightness; Determine a green light test result based on the green light test brightness and the green light standard brightness; Determine a blue light test result based on the blue light test brightness and the blue light standard brightness; Based on the red light test result, the green light test result and the blue light test result, a lamp bead aging test result of the LED module to be tested is determined.

5. The method according to claim 4, characterized in that When the temperature is the preset aging temperature, a single LED lamp bead of the LED module to be tested is subjected to an aging test of red, green and blue light according to the preset aging time to obtain corresponding red light test brightness, green light test brightness and blue light test brightness, including: Based on the preset aging temperature, the preset aging time and the first aging current, performing a red light aging test on the first LED lamp bead of the LED module to be tested to obtain the red light test brightness; Based on the preset aging temperature, the preset aging time and the second aging current, performing a green light aging test and a blue light aging test on the second LED lamp bead of the LED module to be tested, and obtaining the corresponding green light test brightness and the blue light test brightness; Wherein, both the first aging current and the second aging current are greater than the standard use current of a single LED lamp bead of the LED module to be tested.

6. The method according to claim 4, characterized in that Based on the red light test brightness and the red light standard brightness, determining a red light test result, including: when the red light test brightness is greater than or equal to a preset multiple of the red light standard brightness, the red light test result is that the red light test is passed; Based on the green light test brightness and the green light standard brightness, determining a green light test result, including: when the green light test brightness is greater than or equal to a preset multiple of the green light standard brightness, the green light test result is that the green light test is passed; Determining a blue light test result based on the blue light test brightness and the blue light standard brightness, including: when the blue light test brightness is greater than or equal to a preset multiple of the blue light standard brightness, the blue light test result is that the blue light test is passed; Based on the red light test result, the green light test result and the blue light test result, determining the lamp bead aging test result of the LED module to be tested, including: when the red light test result, the green light test result and the blue light test result are all passed, the lamp bead aging test result of the LED module to be tested is passed the aging test.

7. The method according to claim 3, characterized in that Comparing the test brightness of the LED module to be tested with the standard brightness to obtain a brightness test result, including: when the test brightness of the LED module to be tested is greater than or equal to a preset multiple of the standard brightness, the brightness test result is that the brightness test is passed; Based on the brightness test result and the lamp bead aging test result, the color cast detection result of the LED module to be tested is determined, including: when the brightness test result and the lamp bead aging test result are both passed, the color cast detection result of the LED module to be tested is passed.

8. A method for detecting color cast of a lamp bead bracket of an LED module, characterized in that: include: Based on the target lighting duration of the LED lamp beads, control the number of reflow soldering and the maximum temperature of each reflow soldering; Based on the number of reflow soldering times and the maximum temperature, the assembly to be soldered is soldered and heated to obtain an LED module in a target state, wherein the assembly to be soldered is obtained by attaching the LED lamp bead to a PCB module board; Performing a whiteness test on the lamp bead bracket to be tested of the LED module to obtain a test whiteness of the lamp bead bracket to be tested; Compare the test whiteness of the lamp bead bracket to be tested with the standard whiteness to determine the color cast detection result of the lamp bead bracket to be tested.

9. The method according to claim 8, characterized in that Comparing the tested whiteness of the lamp bead bracket to be tested with the standard whiteness to determine the color cast detection result of the lamp bead bracket to be tested, including: Compare the tested whiteness of the lamp bead bracket to be tested with the standard whiteness to obtain a whiteness test result; Determine the color cast detection result of the lamp bead bracket to be tested based on the whiteness test result; Alternatively, an aging test is performed on a single LED lamp bead of the LED module to obtain a lamp bead aging test result; Based on the whiteness test result and the lamp bead aging test result, the color cast detection result of the lamp bead bracket to be tested is determined.

10. A method for detecting color cast of packaging adhesive of an LED module, characterized in that: include: Based on the target lighting duration of the LED lamp beads, control the number of reflow soldering and the maximum temperature of each reflow soldering; Based on the number of reflow soldering and the maximum temperature, the glue cake is heated to obtain a glue cake to be tested in a target state, wherein the glue cake is a glue cake obtained by processing the packaging glue to be tested of the LED module; Performing a whiteness test on the rubber cake to be tested to obtain a test whiteness of the rubber cake to be tested; The test whiteness of the tested adhesive cake is compared with the standard whiteness to determine the color cast detection result of the tested packaging adhesive.

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