LED glass cement compatibility test method

Abstract

The invention discloses an LED glass cement compatibility testing method, and relates to the technical field of LED testing, and the method comprises the steps: welding an LED at the center of a PCB; uniformly coating the bottom of the high-temperature-resistant glass bottle with glass cement, and after the surface of the glass cement is dried, enabling the opening of the high-temperature-resistant glass bottle to face downwards, surrounding the LED and inversely buckling the high-temperature-resistant glass bottle on the PCB; glass cement consistent with the bottle bottom is smeared on the peripheral side of a bottle opening of the high-temperature-resistant glass bottle, so that the LED and the glass cement at the bottle bottom are sealed in the closed space; putting the LED glass cement compatibility test device into a high-low temperature test box, setting the temperature to be 80 DEG C, the heating time to be 20 minutes and the relative humidity to be 50%, and performing constant-temperature aging for 500 hours; taking out the aged LED glass cement compatibility test device from the high-low temperature test box, separating the high-temperature-resistant glass bottle from the PCB, communicating a positive lead and a negative lead of the PCB with a circuit, electrifying the LED, measuring the aged color temperature value, and calculating whether the color temperature change rate, the color rendering index and the color tolerance of the LED reach set thresholds or not.

Description

Technical Field

[0001] This application belongs to the field of LED testing technology, specifically relating to a method for testing the compatibility of LED glass adhesive. Background Technology

[0002] In actual production and application, LED lighting fixtures typically require encapsulation or fixation with silicone sealant. However, over long-term use, the sealant can affect the light output and transmittance of the LED light source, directly impacting the LED's lifespan and overall product quality. With a wide variety of silicone sealants available on the market, varying greatly in quality, selecting the most suitable sealant for LED lighting fixtures is difficult and usually requires extensive use to determine the optimal choice.

[0003] Currently, factories typically use long-term aging tests to select silicone sealant for LEDs before they leave the factory. This method involves manufacturing the LED and sealant as finished products, placing them in an outdoor environment for extended aging to simulate the usage environment, then powering the LEDs on and off, and periodically testing the color temperature of the LEDs to determine compatibility with the sealant. However, this long-term aging test method has significant drawbacks: First, the testing cycle is too long, requiring at least one year. Different manufacturers' sealants release different chemicals during the curing process, resulting in varying degrees of chemical contamination to the LEDs, making the test results inaccurate due to environmental changes. Second, intense competition in the silicone sealant market and foreign regulations on raw materials lead manufacturers to frequently adjust their formulas, increasing the cost of such a lengthy testing process. Furthermore, after testing, the original manufacturer may have changed its formula, making it difficult to accurately match the test results with existing sealant models, resulting in inaccurate results. Therefore, a method for quickly testing the compatibility between silicone sealant and LEDs is needed, allowing for rapid matching of LEDs with suitable sealants. Summary of the Invention

[0004] This application provides a compatibility testing method for LED glass sealant to solve the aforementioned problems of excessively long testing cycles, inconsistent chemical substances volatilized by the glass sealant due to external environmental influences over long periods, resulting in inaccurate test results, and continuous changes in glass sealant formulations causing the testing cycle to lag behind the pace of formulation changes, thus making it impossible to obtain timely test results that match the glass sealant.

[0005] The technical solution adopted in this application is as follows:

[0006] A method for testing the compatibility of LED glass adhesive, comprising the following steps:

[0007] Solder the LED to the center of the PCB board;

[0008] Apply silicone sealant evenly to the bottom of the high-temperature resistant glass bottle. After the sealant has dried, place the bottle upside down on the PCB board with the bottle opening facing down around the LED.

[0009] Apply silicone sealant around the mouth of the high-temperature resistant glass bottle, matching the sealant on the bottom of the bottle, to seal the LED and the sealant on the bottom of the bottle in a sealed space.

[0010] The LED glass glue compatibility test device was placed in a high and low temperature test chamber, the temperature was set to 80℃, the heating time was 20 minutes, the relative humidity was 50%, and the constant temperature aging was carried out for 500 hours.

[0011] Remove the aged LED glass adhesive compatibility testing device from the high and low temperature test chamber, separate the high temperature resistant glass bottle from the PCB board, connect the positive and negative leads of the PCB board to the circuit, so that the LED is powered on, measure the color temperature value after aging, and calculate whether the color temperature change rate, color rendering index and color tolerance have reached the set threshold.

[0012] Before placing the LED glass glue compatibility testing device into the high and low temperature test chamber, the original color temperature is tested. A spectroradiometer is used to test the color temperature of the LED after welding. The input voltage is DC6V and the current is 120mA. After 10 minutes of power-on, the original color temperature value, original color rendering index and original color tolerance data of the LED are measured.

[0013] The formula for calculating the color temperature change rate is: Color temperature change rate = (Color temperature value after aging - Original color temperature value) / Original color temperature value; If the calculated color temperature change rate is within ±5%, the glass glue is determined to be compatible with the LED light source; otherwise, the glass glue is determined to be incompatible with the LED light source.

[0014] If the original color rendering index is greater than Ra70, and the color rendering index after aging is greater than or equal to Ra70, then the glass adhesive is considered compatible with the LED light source; otherwise, the glass adhesive is considered incompatible with the LED light source.

[0015] If the original color tolerance is less than 5 sdcm and the color tolerance after aging is also less than 5 sdcm, then the sealant is considered compatible with LEDs and light sources; otherwise, the sealant is considered incompatible with LED light sources.

[0016] Before placing the LED glass glue compatibility testing device into the high and low temperature test chamber, the measurement also includes the forward voltage change rate and the luminous intensity change rate. When the forward voltage change rate and the luminous intensity change rate are within the set threshold range, the glass glue is determined to be compatible with the LED light source; otherwise, the glass glue is determined to be incompatible with the LED light source.

[0017] The PCB board includes a board body and a copper foil assembly connected to the board body. The copper foil assembly includes an outer ring and a support. The outer ring has a circular structure, and the support has a straight structure. The mouth of the high-temperature resistant glass bottle is bonded to the outer ring with glass glue. The support is connected to the outer ring, and an LED is connected to the center of the support. One end of the support is connected to the positive lead, and the other end of the support is connected to the negative lead. The positive and negative leads extend outside the high-temperature resistant glass bottle.

[0018] The height and width of the silicone sealant used to bond the mouth of the high-temperature resistant glass bottle to the PCB board shall not be less than 4mm.

[0019] The weight range for applying silicone sealant to the bottom of high-temperature resistant glass bottles is 20-25g, and the application height range is 8-10mm.

[0020] Before placing the LED glass glue compatibility test device into the high and low temperature test chamber, let the high temperature resistant glass bottle and PCB board stand for 4 hours.

[0021] Due to the adoption of the above technical solution, the beneficial effects achieved by this application are as follows:

[0022] 1. This application discloses a method for testing the compatibility of LED glass adhesive, comprising: soldering an LED to the center of a PCB board; uniformly applying glass adhesive to the bottom of a high-temperature resistant glass bottle; after the glass adhesive surface dries, inverting the high-temperature resistant glass bottle with its opening facing downwards, surrounding the LED on the PCB board; applying glass adhesive of the same consistency as the bottom of the bottle to the circumference of the bottle opening to seal the LED and the glass adhesive at the bottom of the bottle in a sealed space; placing the LED glass adhesive compatibility testing device in a high and low temperature test chamber, setting the temperature to 80°C, the heating time to 20 minutes, the relative humidity to 50%, and aging at a constant temperature for 500 hours; removing the aged LED glass adhesive compatibility testing device from the high and low temperature test chamber, separating the high-temperature resistant glass bottle from the PCB board, connecting the positive and negative leads of the PCB board to the circuit, so that the LED is powered on, measuring the color temperature value after aging, and calculating whether the LED color temperature change rate, color rendering index, and color tolerance have reached the set threshold.

[0023] This application can simulate the heating and aging environment of LEDs and reasonably control the external environmental conditions of LEDs, making the glass glue a variable condition. This allows for a strong correlation between the performance parameters of the LEDs and the glass glue, enabling accurate determination of the influence of the glass glue on the performance parameters of LEDs and the impact of different types of glass glue on the compatibility of LED lamps. The compatibility between the glass glue and LEDs can be determined from three aspects: color temperature, color rendering parameters, and color tolerance. This achieves rapid, accurate, and efficient testing, saving manpower and resources.

[0024] 2. This application, by setting reasonable pretreatment and accelerated aging conditions, can reflect the long-term usage of LEDs and glass adhesives in a shorter time. Compared with traditional long-term aging test methods, it significantly shortens the test cycle from over one year to 500 hours, effectively improving the efficiency of product development and production and reducing time costs. Furthermore, by comprehensively considering multiple data such as the LED's correlated color temperature, color rendering index, and color tolerance, it assesses the compatibility of LEDs and glass adhesives from multiple dimensions. Through precise testing and comparative analysis of data before and after aging, potential compatibility issues can be accurately identified, avoiding misjudgments caused by single performance tests and improving the reliability of test results. In addition, the shortened test cycle reduces the consumption of manpower, material resources, and energy, lowering the company's testing costs. Simultaneously, rapid test results allow companies to adjust product design and production processes promptly, avoiding product quality problems and production waste caused by using incompatible LEDs and glass adhesives, further saving costs. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is an exploded structural diagram of an LED glass adhesive compatibility testing device according to one embodiment of this application;

[0027] Figure 2 This is a schematic diagram of an LED glass adhesive compatibility testing device without a high-temperature resistant glass bottle, according to one embodiment of this application.

[0028] Figure 3 This is a schematic diagram of the assembly structure of an LED glass adhesive compatibility testing device according to one embodiment of this application;

[0029] Figure 4 This application provides a compatibility test method for LED glass sealant, which is used to analyze the compatibility between LEDs and brand A glass sealant.

[0030] Figure 5 A compatibility analysis table for testing the compatibility between LEDs and Brand B glass adhesive using the LED glass adhesive compatibility test method of this application;

[0031] In the picture,

[0032] 1. PCB board; 2. LED; 3. High-temperature resistant glass bottle; 4. Glass glue; 5. Copper foil assembly; 51. Outer ring; 52. Bracket; 6. Positive lead; 7. Negative lead. Detailed Implementation

[0033] To more clearly illustrate the overall concept of this application, a detailed explanation is provided below with reference to the accompanying drawings.

[0034] Many specific details are set forth in the following description in order to provide a full understanding of this application. However, this application may also be implemented in other ways different from those described herein. Therefore, the scope of protection of this application is not limited to the specific embodiments disclosed below.

[0035] Furthermore, it should be understood in the description of this application that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0036] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0037] In this application, unless otherwise expressly specified and limited, the "above" or "below" of the second feature can mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. In the description of this specification, references to terms such as "implementation," "example," "a particular embodiment," "example," or "specific example," etc., indicate that the specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples.

[0038] like Figure 1-5 As shown, this application relates to a method for testing the compatibility of LED glass adhesive, the steps of which include:

[0039] Solder the LED to the center of the PCB board;

[0040] Apply silicone sealant evenly to the bottom of the high-temperature resistant glass bottle. After the sealant has dried, place the bottle upside down on the PCB board with the bottle opening facing down around the LED.

[0041] Apply silicone sealant around the mouth of the high-temperature resistant glass bottle, matching the sealant on the bottom of the bottle, to seal the LED and the sealant on the bottom of the bottle in a sealed space.

[0042] The LED glass glue compatibility test device was placed in a high and low temperature test chamber, the temperature was set to 80℃, the heating time was 20 minutes, the relative humidity was 50%, and the constant temperature aging was carried out for 500 hours.

[0043] Remove the aged LED glass glue compatibility testing device from the high and low temperature test chamber, separate the high temperature resistant glass bottle from the PCB board, connect the positive and negative leads of the PCB board to the circuit, so that the LED is powered on, measure the color temperature value of the LED after the glass glue has aged, and calculate whether the color temperature change rate, color rendering index and color tolerance of the LED have reached the set threshold.

[0044] In the production process of LED lighting products, silicone sealant is often used to seal and fix LED lamps. However, after long-term use, the sealant can affect the light output and transmittance of the LED light source, directly impacting the LED's lifespan and product quality. Therefore, selecting the best silicone sealant that matches the LED from among numerous brands is crucial. Currently, the compatibility test between LEDs and silicone sealant uses a long-term aging test method. This method involves manufacturing the LED and silicone sealant as finished products, placing them in an outdoor environment for extended aging to simulate the usage environment. The LED lamps are then powered on and off, and the relevant color temperature values ​​are periodically tested to determine compatibility. However, this long-term aging test method has significant drawbacks: First, the testing period is too long, requiring at least one year for outdoor aging. Second, different manufacturers' silicone sealants release different chemicals during the curing process, resulting in varying degrees of chemical contamination to the LED lamps. The test results are subject to environmental changes, making it impossible to draw accurate conclusions. Moreover, the long waiting period affects the progress of product research and development and production. Furthermore, due to the intense competition in the glass sealant market and foreign control over raw materials, glass sealant manufacturers frequently adjust their formulas. Therefore, such a long testing process requires a lot of manpower and resources, increasing the cost of testing. Moreover, after the test is completed, the original manufacturer has changed to a new formula, making it impossible to accurately match the test results with the existing glass sealant models, resulting in inaccurate test results. Therefore, it is necessary to design a testing method that can quickly determine which glass sealant is most suitable for LED lighting fixtures, enabling LEDs to quickly find the appropriate glass sealant.

[0045] In the existing patent technology, the patent title is "A Packaging Method for a Dual-Temperature COB Light Source and a Dual-Temperature COB Light Source". It discloses a packaging method for COB light sources, but does not provide a specific testing method for which type of glass adhesive is most suitable for LEDs. Therefore, based on the above-mentioned technical problems, this application relates to an LED glass adhesive compatibility testing method, which enables LEDs to be matched with the most suitable glass adhesive and avoids inaccurate test results due to long-term testing.

[0046] The testing process begins with the installation of an LED glass adhesive compatibility testing device. This device is then subjected to heat aging treatment. Following this heat aging, the device is retested, measuring the correlated color temperature change rate, color rendering index, and color tolerance of the LED, as well as the forward voltage change rate and luminous intensity change rate. The measured data are compared to normal thresholds. If the data falls within the threshold range, the glass adhesive is considered compatible with the LED lighting fixture; otherwise, it is considered incompatible. Furthermore, all qualified correlated color temperature change rate, color rendering index, color tolerance, forward voltage change rate, and luminous intensity change rate can be compared. The data on the rate of change of temperature were organized to obtain the optimal glass glue as the first choice for the most suitable glass glue for the LED lamp. The LED glass glue compatibility testing device used in this application can measure various data after 500 hours of constant temperature aging in a high and low temperature test chamber. This data serves as the basis for testing whether the glass glue has compatibility. Only 500 hours are needed to obtain an accurate compatibility judgment, avoiding the problem of judging whether the glass glue is compatible after a year of use. This greatly shortens the judgment cycle and can accurately judge whether the glass glue is compatible with the LED through data. The ambient temperature is controlled to avoid the problem of inaccurate measurement results caused by excessive interference from external uncertainties when the glass glue is placed outdoors for a year, as is the case with traditional glass glue.

[0047] It should be noted that the glass sealant referred to in this application is a one-component silicone adhesive sealant.

[0048] The LED glass adhesive compatibility testing device used in this application includes a PCB board, a high-temperature resistant glass bottle, an LED, and glass adhesive. The PCB board includes a board body and a copper foil assembly connected to the board body. The copper foil assembly includes an outer ring and a support. The outer ring has a circular structure, and the support has a linear structure. The support is connected to the outer ring radially, and an LED is connected to the center of the support. One end of the support extends beyond the outer ring and is connected to the positive lead, and the other end of the support extends beyond the outer ring and is connected to the negative lead. A uniform thickness of glass adhesive is applied to the bottom of the high-temperature resistant glass bottle. The bottle opening is adhered to the PCB board with glass adhesive and is located outside the outer ring, thus forming a sealed space inside the high-temperature resistant glass bottle. The positive and negative leads extend beyond the outer ring. The LED and part of the support are sealed inside the high-temperature glass bottle. The positive and negative leads extend out of the high-temperature glass bottle to allow for power-on testing to test the performance changes of the LED. The color temperature, color tolerance, color rendering index, luminous intensity, and forward voltage of the LED measured before aging are recorded as raw data. The color temperature, color tolerance, color rendering index, luminous intensity, and forward voltage of the LED measured after aging are compared with the recorded raw data to determine whether there is compatibility between the obtained glass sealant and the LED lamp. The glass sealant with the best data value among the obtained compatible glass sealants is selected as the most suitable glass sealant for the LED lamp.

[0049] To enhance sealing performance, a circular groove is made on the PCB board to facilitate the welding of the outer ring into the circular groove. A square groove, connected to the circular groove, is located at the center of the circular groove in the radial direction. The two ends of the square groove extend beyond the circular groove and are symmetrically arranged. A bracket is welded into the square groove, with a positive lead connected to one end of the bracket and a negative lead connected to the other end. This arrangement ensures that during the connection between the high-temperature resistant glass bottle and the outer ring, the bottle opening and the PCB board are at the same level, enhancing the sealing between the high-temperature resistant glass bottle and the PCB board and preventing glue from seeping into the high-temperature resistant glass bottle.

[0050] To further address the issue of adhesive seeping into the high-temperature resistant glass bottle and affecting test results when applied between the bottle opening and the PCB board, this application employs various implementation methods, including but not limited to the following:

[0051] In the first embodiment, an annular groove is formed on the periphery of the PCB board. The annular groove is located on the outer periphery of the copper foil assembly on the PCB board. The high-temperature resistant glass bottle can be embedded in the annular groove. The glass component at the bottom of the high-temperature resistant glass bottle is coated between the high-temperature resistant glass bottle and the side wall of the annular groove, so that the high-temperature resistant glass bottle is sealed in the annular groove. This covers the outer periphery of the copper foil assembly on the PCB board and forms a sealed space inside the high-temperature resistant glass bottle, encapsulating the LED lamp in the high-temperature resistant glass bottle.

[0052] In the second embodiment, a first enclosure is connected to the periphery of the LED, and the first enclosure is filled with the same glass glue as that in a high-temperature resistant glass bottle; or the first enclosure is set as a raised ring around the LED, and there is no filling material inside.

[0053] To obtain multiple compatibility test results for glass adhesives and LED lights in a single test, a PCB board can be set up with multiple copper foil components. Each copper foil component is connected to a high-temperature resistant glass bottle. Glass adhesives from different manufacturers are applied to each high-temperature resistant glass bottle to determine whether there is compatibility between glass adhesives from different brands and manufacturers and the LED lights.

[0054] As a preferred embodiment, before placing the LED glass glue compatibility testing device into the high and low temperature test chamber, the original color temperature is tested. The color temperature of the LED after welding is tested using a spectroradiometer with an input voltage of DC6V and a current of 120mA. After being powered on for 10 minutes, the original color temperature value, original color rendering index and original color tolerance data of the LED are measured.

[0055] After installing the LED glass adhesive compatibility testing device, the raw data is tested first, including but not limited to color temperature, color tolerance, color rendering index, luminous intensity, and forward voltage. A high-precision rapid spectroradiometer is used to test the relevant data after the LEDs are soldered on the bracket. When soldering 3030 LEDs, the input voltage is DC 5.8V and the current is 0.5 mA; when soldering 5050 LEDs, the input voltage is DC 24V and the current is 0.5 mA. After stabilizing for 10 minutes, the LED's relevant color temperature, color rendering index, and color tolerance data are tested. This test can obtain the raw data values ​​of LEDs from different manufacturers before aging, and the relevant data after the test are recorded, including the raw color temperature, raw color tolerance, raw color rendering index, raw luminous intensity, and raw forward voltage.

[0056] As a preferred implementation method, the formula for calculating the temperature change rate is: color temperature change rate = (color temperature value after aging - original color temperature value) / original color temperature value; if the calculated color temperature change rate is within ±5%, the glass glue is determined to be compatible with the LED light source; otherwise, the glass glue is determined to be incompatible with the LED light source.

[0057] Color temperature changes can affect LED lighting fixtures and may lead to a loss of luminous efficacy. Yellowing and aging of silicone sealant can cause color temperature shifts, resulting in changes in the brightness of the light emitted by LED lighting fixtures. Moreover, it can easily cause sudden color temperature changes, affecting the quality of use and energy efficiency. Therefore, by determining the color temperature change rate before and after LED aging, we can determine whether the silicone sealant meets the requirements for LED use, thereby judging whether it is compatible with LEDs and finding the optimal silicone sealant.

[0058] In a preferred embodiment, if the original color rendering index is greater than Ra70 and the color rendering index after aging is greater than or equal to Ra70, then the glass adhesive is determined to be compatible with the LED light source; otherwise, the glass adhesive is determined to be incompatible with the LED light source.

[0059] The color rendering index (CRI) is an important indicator of whether an LED's emitted light source can reproduce the true colors of an object. The quality of the silicone sealant also affects the LED's ability to reproduce the true colors of an object. The silicone sealant may reduce the CRI of the LED through absorption spectrum, refractive index mismatch, or yellowing due to aging. Therefore, to determine whether the silicone sealant is compatible with the LED, it is also necessary to determine the CRI. If the original CRI of the LED is greater than Ra70, and its CRI is still greater than Ra70 after heat aging treatment, it can be determined that it will not reduce the color rendering ability of the LED, thus determining that the silicone sealant and the LED are compatible.

[0060] In a preferred embodiment, if the original color tolerance is less than 5 sdcm and the color tolerance after aging is also less than 5 sdcm, then the glass sealant is determined to be compatible with LEDs and light sources; otherwise, the glass sealant is determined to be incompatible with LED light sources.

[0061] Color tolerance values ​​can affect the color consistency of LED lights, especially after the LED and the silicone sealant age, as the latter absorbs short-wavelength light, causing a decrease in color temperature and an increase in color tolerance over time. This leads to inconsistent light colors in the LED lights, potentially resulting in a multicolored effect in the same scene and a decrease in color rendering. Therefore, testing the color tolerance to determine if it falls within a set threshold is crucial for assessing the compatibility between the LED and the silicone sealant. If the color tolerance value of the heated and aged LED is too high or too low, it will affect the color consistency and light transmittance of the LED light fixture, indicating that it does not meet compatibility requirements.

[0062] In a preferred embodiment, before placing the LED glass glue compatibility testing device into the high and low temperature test chamber, the measurement further includes measuring the forward voltage change rate and the luminous intensity change rate; when the forward voltage change rate and the luminous intensity change rate are within the set threshold range, the glass glue is determined to be compatible with the LED light source; otherwise, the glass glue is determined to be incompatible with the LED light source.

[0063] Specifically, the formula for calculating the forward voltage change rate is: forward voltage change rate = (forward voltage after aging - initial forward voltage) / initial forward voltage × 100%, and the formula for calculating the luminous intensity change rate is: luminous intensity change rate = (luminous intensity after aging - initial luminous intensity) / initial luminous intensity × 100%.

[0064] The impact of forward voltage on LED lighting fixtures is indirectly caused by changes in the LED's heat dissipation performance, electrical contact, or material chemical compatibility. To achieve the best glass sealant compatibility with LED lighting fixtures, it is necessary to measure the forward voltage of the LED. The voltage required for an LED to conduct at its rated current is typically 2.8V–3.6V. The stability of the forward voltage directly affects the LED's energy efficiency, light color consistency, and driver circuit design. If the glass sealant has poor thermal conductivity, it will increase the LED's thermal resistance, leading to an increase in junction temperature. Moreover, the acetic acid contained in the glass sealant may corrode the LED electrodes or solder joints, thereby increasing the forward voltage. Therefore, it is necessary to measure whether the rate of change of forward voltage is within the normal threshold to determine whether the glass sealant is compatible with the LED and to determine the best-fitting glass sealant.

[0065] Testing luminous intensity can indirectly reflect the impact of silicone sealant on the light transmittance of LED lamps. If the light transmittance of the silicone sealant is lower than that of the LED encapsulation material, it will lead to a reduction in the light output of the LED. Scattering within the silicone sealant or interface reflection will affect its light transmittance. Moreover, aged silicone sealant will absorb blue light, reducing the luminous intensity of white LED lamps. Therefore, a photometer or infrared thermal imager can be used to detect luminous intensity. By detecting the luminous intensity of the LED before and after aging, it can be reflected whether it has a significant impact on the light transmittance and luminous efficacy of the LED lamp. If the measured rate of change of luminous intensity is within the set threshold range, i.e., less than 0.6%, it can be determined that the silicone sealant is suitable for the LED lamp and has compatibility with the LED lamp.

[0066] As a preferred embodiment, the height and width of the glass adhesive used to bond the mouth of the high-temperature resistant glass bottle to the PCB board are not less than 4mm.

[0067] The purpose of using the same silicone sealant applied to the bottom of the high-temperature resistant glass bottle to bond the bottle mouth to the PCB board is to seal the high-temperature resistant glass bottle into a sealed space, preventing the LED lights inside from being affected by the external high-temperature environment. This ensures that the silicone sealant used in the tests is consistent, guaranteeing the accuracy and consistency of the test results.

[0068] As a preferred embodiment, the mass of the silicone sealant applied to the bottom of the high-temperature resistant glass bottle is 20-25g, the application height is 8-10mm, and at least 20 minutes are allowed for the silicone sealant to dry in the high-temperature resistant glass bottle.

[0069] After applying the silicone sealant to the inside of the glass bottle, it is necessary to wait for it to dry before testing. This is because uncured silicone sealant still contains volatile substances that can affect the test results. Furthermore, the presence of acidic substances in the sealant can release corrosive gases, causing electrical tests to fail and affecting the test results. There is also a risk of electrical conductivity. In addition, the refractive index of light differs between the silicone sealant before and after curing. If it is not cured, it will affect the measurement results of parameters such as light efficacy and color temperature, leading to inaccurate measurement results.

[0070] As a preferred embodiment, the high-temperature resistant glass bottle and the PCB board are left to stand for 4 hours before the LED glass glue compatibility test device is placed in the high and low temperature test chamber.

[0071] Four hours after the high-temperature resistant glass bottle was bonded to the PCB board, the combined sample was placed in a high and low temperature test chamber. The high temperature was set to 80°C, the heating time was 20 minutes, the relative humidity was 50%, and the constant temperature aging was completed for 500 hours. The components did not need to be powered during the aging process. By aging in a high-temperature environment, the compatibility issues between LEDs and glass glue during long-term use can be simulated in a shorter time, and the potential problems can be revealed more quickly.

[0072] like Figure 4-5 As shown, by using the above-mentioned LED glass glue compatibility test method to measure the compatibility between glass glue of brands A and B and LEDs, respectively, measuring color temperature, color rendering index and color tolerance can reflect whether the glass glue is suitable for the LED lamp and whether there is compatibility between the glass glue and the LED. In practical applications, performing the same test on many brands can determine the optimal glass glue, and the most suitable glass glue for LEDs can be determined quickly in a short time.

[0073] For any parts not mentioned in this application, existing technologies may be used or referenced.

[0074] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0075] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for testing the compatibility of LED glass adhesive, characterized in that the steps include... include: Solder the LED to the center of the PCB board; Apply silicone sealant evenly to the bottom of the high-temperature resistant glass bottle. After the sealant has dried, place the bottle upside down on the PCB board with the bottle opening facing down around the LED. Apply silicone sealant around the mouth of the high-temperature resistant glass bottle, matching the sealant on the bottom of the bottle, to seal the LED and the sealant on the bottom of the bottle in a sealed space. The LED glass glue compatibility test device was placed in a high and low temperature test chamber, the temperature was set to 80℃, the heating time was 20 minutes, the relative humidity was 50%, and the constant temperature aging was carried out for 500 hours. Remove the aged LED glass adhesive compatibility testing device from the high and low temperature test chamber, separate the high temperature resistant glass bottle from the PCB board, connect the positive and negative leads of the PCB board to the circuit, so that the LED is powered on, measure the color temperature value after aging, and calculate whether the LED color temperature change rate, color rendering index and color tolerance have reached the set threshold.

2. The LED glass adhesive compatibility testing method as described in claim 1, characterized in that, Before placing the LED glass glue compatibility testing device into the high and low temperature test chamber, the original color temperature is tested. A spectroradiometer is used to test the color temperature of the LED after welding. The input voltage is DC6V and the current is 120mA. After 10 minutes of power-on, the original color temperature value, original color rendering index and original color tolerance data of the LED are measured.

3. The LED glass adhesive compatibility testing method as described in claim 2, characterized in that, The formula for calculating the color temperature change rate is: Color temperature change rate = (Color temperature value after aging - Original color temperature value) / Original color temperature value; If the calculated color temperature change rate is within ±5%, the glass glue is determined to be compatible with the LED light source; otherwise, the glass glue is determined to be incompatible with the LED light source.

4. The LED glass adhesive compatibility testing method as described in claim 2, characterized in that, If the original color rendering index is greater than Ra70, and the color rendering index after aging is greater than or equal to Ra70, then the glass adhesive is considered compatible with the LED light source; otherwise, the glass adhesive is considered incompatible with the LED light source.

5. The LED glass adhesive compatibility testing method as described in claim 2, characterized in that, If the original color tolerance is less than 5 sdcm and the color tolerance after aging is also less than 5 sdcm, then the sealant is considered compatible with LEDs and light sources; otherwise, the sealant is considered incompatible with LED light sources.

6. The LED glass adhesive compatibility testing method as described in claim 1, characterized in that, Before placing the LED glass glue compatibility testing device into the high and low temperature test chamber, the measurement also includes the forward voltage change rate and the luminous intensity change rate. When the forward voltage change rate and the luminous intensity change rate are within the set threshold range, the glass glue is determined to be compatible with the LED light source; otherwise, the glass glue is determined to be incompatible with the LED light source.

7. The LED glass adhesive compatibility testing method as described in claim 1, characterized in that, The PCB board includes a board body and a copper foil assembly connected to the board body. The copper foil assembly includes an outer ring and a support. The outer ring has a circular structure, and the support has a straight structure. The mouth of the high-temperature resistant glass bottle is bonded to the outer ring with glass glue. The support is connected to the outer ring, and an LED is connected to the center of the support. One end of the support is connected to the positive lead, and the other end of the support is connected to the negative lead. The positive and negative leads extend outside the high-temperature resistant glass bottle.

8. The LED glass adhesive compatibility testing method as described in claim 1, characterized in that, The height and width of the silicone sealant used to bond the mouth of the high-temperature resistant glass bottle to the PCB board shall not be less than 4mm.

9. The LED glass adhesive compatibility testing method as described in claim 1, characterized in that, The weight range for applying silicone sealant to the bottom of high-temperature resistant glass bottles is 20-25g, and the application height range is 8-10mm.

10. The LED glass adhesive compatibility testing method as described in claim 1, characterized in that, In the accelerated aging process, the high-temperature resistant glass bottle and the PCB board are left to stand for 4 hours before the LED glass glue compatibility test device is placed in the high and low temperature test chamber.

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