Illumination LED light source suitable for old people and preparation method thereof

Abstract

The invention provides a lighting LED light source suitable for old people, which comprises a bracket, a chip and fluorescent glue, a bowl cup is arranged on the bracket, a functional area is arranged at the bottom in the bowl cup, the functional area comprises two conductive parts and an insulating part, and the two conductive parts are insulated and separated through the insulating part positioned in the center of the bowl cup; a first LED chip and a second LED chip are arranged in the bowl cup, and the first LED chip and the second LED chip are electrically connected in series; the bowl cup is filled with the fluorescent glue, and the functional area, the first LED chip and the second LED chip are covered with the fluorescent glue; the fluorescent glue is a mixed solution of silica gel and fluorescent powder, and the fluorescent powder comprises first fluorescent powder, second fluorescent powder, third fluorescent powder and fourth fluorescent powder; according to the illumination LED light source suitable for the old, the spectrum fitting degree coefficient GFC is equal to 0.82, and the color rendering authenticity and the visual comfort degree are remarkably improved. Rhythm factor M / Pratio is equal to 0.75, melatonin secretion regulation is optimized, and sleep quality is improved. The visual sensitivity SP value is 2.6, and color identification deviation caused by crystalline lens yellowing is reduced.

Description

Technical Field

[0001] This invention relates to the field of LED light source technology, and in particular to an age-friendly LED light source and its preparation method. Background Technology

[0002] As people age, their visual abilities gradually decline. The lens yellows and hardens, significantly reducing the transmittance of short-wavelength blue light. Simultaneously, the function of retinal photoreceptor cells deteriorates, the pupil constricts, and the amount of light entering the eye decreases, leading to significant differences in their lighting requirements compared to younger people. Furthermore, older adults are prone to circadian rhythm disruptions and decreased sleep quality. Therefore, age-appropriate lighting should not only provide sufficient visual brightness but also have the function of regulating rhythms and promoting health.

[0003] Current lighting products for the elderly often focus on increasing light source brightness to compensate for the degeneration of photoreceptor cells in older adults. This not only wastes energy but also causes damage to the retina due to excessively high blue light energy in the spectrum. These types of light sources only provide simple illumination and lack circadian rhythm regulation, thus failing to improve sleep problems commonly experienced by many elderly people.

[0004] Existing technologies attempt to achieve spectral tunability through dual-color-temperature or multi-channel LED combinations. For example, Chinese patent document CN117690917A uses a combination of chip groups with two extreme color temperatures of 2200K and 8500K. Although it achieves high and low color temperature switching, its low color temperature M / P value (0.2661) is significantly lower than that of sunlight at the same color temperature (0.3788). Although it is beneficial for rest, its spectrum is biased towards long-wave red light, resulting in poor color rendering and discontinuous spectrum. This makes the ambient light too dim and lacking in vitality. Long-term use may affect mood and exacerbate color recognition difficulties caused by yellowing of the lens.

[0005] For example, Chinese patent document CN222639022U discloses a rhythm-adjustable LED lighting source. This application achieves color temperature and rhythm factor control by setting two functional zones—warm white light and neutral white light—and combining them with different phosphor layers. However, its solution relies on a combination of multiple LED chips with different dominant wavelengths, resulting in a complex structure and high cost. Furthermore, this application requires separate processing of phosphors in the two functional zones within a single cup, making the manufacturing process cumbersome and demanding high precision in isolation and dispensing. Summary of the Invention

[0006] To address the aforementioned problems, this invention discloses an age-friendly LED light source and its preparation method. By employing a specific wavelength blue light chip and a multi-band phosphor system, it simultaneously achieves a high color rendering index, high spectral fitting degree, and a suitable rhythm factor at a conventional color temperature of 4000K. This effectively balances visual health and rhythm regulation needs, solving the problems of extreme color temperature, poor color rendering, and limited rhythm function in existing age-friendly lighting sources.

[0007] The specific technical solution is as follows:

[0008] An age-friendly LED light source includes a bracket, a chip, and fluorescent adhesive. The bracket has a bowl-shaped holder with a functional area at its bottom. The functional area includes two conductive portions and an insulating portion, with the two conductive portions insulated from each other by the insulating portion located at the center of the bowl-shaped holder. A first LED chip and a second LED chip are disposed within the bowl-shaped holder and are connected in series. The bowl-shaped holder is filled with the fluorescent adhesive, which covers the functional area, the first LED chip, and the second LED chip.

[0009] The fluorescent adhesive is a mixed solution of silica gel and phosphor. The silica gel includes adhesive A and adhesive B, and the phosphor includes a first phosphor with a peak wavelength of 537 nm, a second phosphor with a peak wavelength of 558 nm, a third phosphor with a peak wavelength of 600 nm, and a fourth phosphor with a peak wavelength of 631 nm. The weight ratio of silica gel to phosphor is: adhesive A : adhesive B : first phosphor : second phosphor : third phosphor : fourth phosphor = (0.31-0.34) : (1.6-1.7) : (0.17-0.2) :

[0010] (0.13-0.16): (0.34-0.37): (0.03-0.04).

[0011] Furthermore, the first LED chip is a blue light chip with a peak wavelength of 450nm, and the second LED chip is a blue light chip with a peak wavelength of 455nm.

[0012] Furthermore, the chip area ratio of the first LED chip to the second LED chip is 1:1, and the peak spectral light power ratio of the first LED chip to the second LED chip is (0.85-0.9):(0.75-0.8).

[0013] Furthermore, the first phosphor is a green phosphor, the main component of which is Ga-YAG; the second phosphor is a yellow-green phosphor, the main component of which is YAG; the third phosphor is an orange-red phosphor, the main component of which is rare earth silicate; and the fourth phosphor is a red phosphor, the main component of which is tetravalent manganese activated potassium fluorosilicate.

[0014] Furthermore, the first LED chip and the second LED chip are fixed to the bottom of the bowl / cup using die-attach adhesive.

[0015] Furthermore, the positive electrode of the first LED chip is connected to one of the conductive parts via a bonding wire, the negative electrode of the second LED chip is connected to another conductive part via a bonding wire, and the negative electrode of the first LED chip and the positive electrode of the second LED chip are interconnected via bonding wires.

[0016] Furthermore, the bottom of the bracket has two metal electrodes for surface mounting, and the surfaces of the metal electrodes are tin-plated.

[0017] Furthermore, the surfaces of the two conductive parts are plated with silver, the two conductive parts are separated by an insulating part, and the two conductive parts are electrically connected to two metal electrodes respectively.

[0018] This invention also provides a method for preparing an age-friendly LED light source, the specific process of which is as follows:

[0019] Step 1: Apply die bond adhesive to the center of the bottom of the support cup, and place the first LED chip and the second LED chip on the die bond adhesive;

[0020] Step 2: Place the chip-bearing bracket into a constant temperature chamber to cure the die-attach adhesive; the curing temperature is 150℃ and the curing time is 120 minutes, so that the chip is fixed on the bracket.

[0021] Step 3: Using a wire bonding machine, the positive and negative electrodes of each chip are connected to the corresponding functional area on the support or the positive and negative electrodes of adjacent chips.

[0022] Step 4: Prepare a fluorescent gel by mixing phosphor with silica gel. The phosphor is a mixture of green phosphor, yellow-green phosphor, orange-red phosphor, and red phosphor in a certain proportion.

[0023] Step 5: Apply fluorescent adhesive to the bowl / cup, ensuring the fluorescent adhesive completely covers the functional area, chip, and bonding wires;

[0024] Step 6: Place the bracket with the applied adhesive into a constant temperature chamber for staged curing. The first stage curing conditions are: curing temperature 100℃ and curing time 30 minutes; the second stage curing conditions are: curing temperature 130℃ and curing time 60 minutes; the third stage curing conditions are: curing temperature 150℃ and curing time 180 minutes.

[0025] Step 7: Use an LED photoelectric parameter tester to test the photoelectric parameters of the finished LED, and finally obtain an LED light source suitable for elderly lighting.

[0026] The beneficial effects of this invention are reflected in:

[0027] The spectral fit coefficient (GFC) of the LED light source for age-friendly lighting in this invention reaches 0.82, significantly enhancing color rendering accuracy and visual comfort; the circadian rhythm factor (M / P ratio) is 0.75, optimizing melatonin secretion and helping to improve sleep and physiological rhythms; at the same time, the light source has a visual sensitivity efficiency (SP value) of 2.6, effectively improving color perception difficulties caused by yellowing of the lens in the elderly, and has both high luminous efficiency and low blue light characteristics, providing bright and realistic lighting while ensuring eye health and energy saving. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the LED light source for age-friendly lighting in this application.

[0029] Figure 2 This is a side sectional view of this application.

[0030] Figure 3 This is the spectral distribution diagram of the LED light source for age-friendly lighting in this application.

[0031] Figure 4 This is the photoelectric parameter test report of the LED light source for age-friendly lighting in this application.

[0032] Explanation of reference numerals in the attached drawings: 1-bracket, 2-first LED chip, 3-second LED chip, 4-bonding wire, 5-phosphor adhesive, 6-insulating part, 7-conductive part one, 8-conductive part two. Detailed Implementation

[0033] To make the technical solution of the present invention clearer and more explicit, the present invention will be further described below with reference to the accompanying drawings. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Although this specification describes the invention according to embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the various embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0034] This embodiment provides an LED light source for age-friendly lighting, the specific structure of which is as follows: Figures 1 to 2 As shown.

[0035] An age-friendly LED light source includes a bracket 1, a first LED chip 2, a second LED chip 3, bonding wires 4, and fluorescent adhesive 5. A bowl-shaped holder is mounted on the bracket 1. A functional area is located at the bottom of the bowl-shaped holder. This functional area includes two conductive portions with silver-plated surfaces and an insulating portion 6. The conductive portions include conductive portion one 7 and conductive portion two 8. The two conductive portions are insulated from each other by the insulating portion 6 located at the center of the bowl-shaped holder.

[0036] The first LED chip 2 and the second LED chip 3 are respectively fixed to the bottom of the bowl / cup using die-attach adhesive. In this embodiment, the first LED chip 2 is a blue light chip with a peak wavelength of 450nm, a size of 9*18mil, and a peak optical power of 85-90mW; the second LED chip 3 is a blue light chip with a peak wavelength of 455nm, a size of 9*18mil, and a peak optical power of 75-80mW. The chip area ratio of the first LED chip to the second LED chip is 1:1, and the peak spectral optical power ratio between the first LED chip and the second LED chip can be 0.9:0.8, 0.85:0.75, or 0.875:0.775.

[0037] Electrical connection is achieved using wire bonding: the positive electrode of the first LED chip 2 is connected to the conductive part 7 via bonding wire 4; the negative electrode of the second LED chip 3 is connected to the conductive part 8 via bonding wire 4; the negative electrode of the first LED chip 2 and the positive electrode of the second LED chip 3 are connected to each other via bonding wire 4, thereby realizing the series connection of the two chips.

[0038] The bottom of the bracket 1 has two tin-plated metal electrodes for surface mounting. Two conductive parts are electrically connected to these two metal electrodes respectively.

[0039] The bowl is filled with fluorescent adhesive 5, which covers the entire functional area, the first LED chip 2, the second LED chip 3, and all bonding wires 4. The fluorescent adhesive 5 is made of silicone and phosphor mixed in the following weight ratio: A adhesive : B adhesive : first phosphor : second phosphor : third phosphor : fourth phosphor = 0.31 : 1.6 : 0.17 : 0.13 : 0.34 : 0.03; or A adhesive : B adhesive : first phosphor : second phosphor : third phosphor : fourth phosphor = 0.34 : 1.7 : 0.2 : 0.16 : 0.37 : 0.04; or A adhesive : B adhesive : first phosphor : second phosphor : third phosphor : fourth phosphor = 0.325 : 1.65 : 0.185 : 0.145 : 0.355 : 0.035.

[0040] In this formulation, A is the main agent and B is the catalyst; the first phosphor is a green phosphor with a peak wavelength of 537 nm, and its main component is Ga-YAG; the second phosphor is a yellow-green phosphor with a peak wavelength of 558 nm, and its main component is YAG; the third phosphor is an orange-red phosphor with a peak wavelength of 600 nm, and its main component is rare earth silicate; and the fourth phosphor is a red phosphor with a peak wavelength of 631 nm, and its main component is tetravalent manganese-activated potassium fluorosilicate.

[0041] This embodiment also provides a method for preparing an age-friendly LED light source, including the following steps:

[0042] Step 1: Apply die-bonding adhesive to the center of the functional area at the bottom of the support cup, and accurately place the first LED chip and the second LED chip on the die-bonding adhesive;

[0043] Step 2: Place the die-bonded substrate into a constant temperature chamber and cure it at 150℃ for 120 minutes to firmly fix the chip;

[0044] Step 3: Using a fully automated wire bonding machine, gold wire is used for bonding to achieve electrical connection between each chip electrode and its corresponding conductive part or between the chips themselves.

[0045] Step 4: Weigh the silica gel (A and B) and each phosphor according to the above ratio, mix and stir evenly to prepare the fluorescent adhesive, and remove air bubbles by vacuuming.

[0046] Step 5: Apply the prepared fluorescent adhesive to the inside of the bowl to completely cover the functional area, chip, and bonding wires;

[0047] Step 6: Place the dispensing bracket into a constant temperature chamber for segmented curing: first cure at 100℃ for 30 minutes, then cure at 130℃ for 60 minutes, and finally cure at 150℃ for 180 minutes.

[0048] Step 7: After curing, the light source is tested using an LED photoelectric parameter testing system. Once qualified, the light source is sorted and packaged to obtain the LED light source suitable for elderly lighting.

[0049] Figure 3 This is the spectral curve of an age-friendly LED light source in this embodiment. As can be seen from the figure, the peak wavelength of the light power of this invention is located in the 600-650nm range, and the proportion of blue light at 450nm is relatively small, which is less harmful to the retina of the elderly. It fills in the missing cyan component in the spectrum of ordinary white LEDs, resulting in good color rendering and high color fidelity.

[0050] Figure 4 This is the photoelectric parameter test report for Embodiment 1 of this application. As can be seen from the report, the following can be observed:

[0051] 1. The light source of this invention has a color temperature of 4000K pure white light, color crystal coordinates x=0.3889, y=0.3839, color deviation duv=0.00095, and the light color is pure and close to natural light;

[0052] 2. Peak wavelength 629.5nm, color rendering index Ra=92, special color rendering indices R9=59, R12=77, excellent overall color rendering, especially outstanding performance in indices such as R1-R8, R13-R15 (all above 90), and true color reproduction;

[0053] 3. The light source has a luminous efficacy of up to 141.46 lm / W, excellent energy conversion efficiency, and significant energy-saving effect, while the luminous flux is 26.10 lm;

[0054] 4. Electrical parameters show low voltage and low power consumption: forward voltage Vf = 3.060V, forward current If = 60.29mA, power P = 184.5mW, stable operation and high energy efficiency;

[0055] 5. The peak wavelength is 629.5nm, the half-width is 8.7nm, the color purity is 31.94%, the energy spectrum of each wavelength in the spectrum is uniformly distributed, and the fit with the solar spectrum is high. It can significantly improve the color rendering accuracy and visual comfort, and reduce the color recognition deviation caused by yellowing of the lens in the elderly.

[0056] Testing revealed that the spectral fit coefficient (GFC) of the LED light source for age-friendly lighting of this invention reaches 0.82, significantly enhancing color rendering accuracy and visual comfort; the circadian rhythm factor (M / P ratio) is 0.75, optimizing melatonin secretion and helping to improve sleep and physiological rhythms; at the same time, the light source's visual acuity efficiency (SP value) is 2.6, effectively improving color perception difficulties caused by yellowing of the lens in the elderly, and possessing both high luminous efficiency and low blue light characteristics, providing bright and realistic lighting while ensuring eye health and energy saving.

[0057] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An age-friendly LED light source, comprising a bracket, a chip, and fluorescent adhesive, wherein a bowl is disposed on the bracket, and a functional area is provided at the bottom of the bowl, the functional area comprising two conductive parts and an insulating part, the two conductive parts being insulated from each other by the insulating part located at the center of the bowl; characterized in that, The bowl / cup contains a first LED chip and a second LED chip, which are connected in series. The bowl / cup is filled with fluorescent adhesive, which covers the functional area, the first LED chip, and the second LED chip. The fluorescent adhesive is a mixed solution of silica gel and phosphor. The silica gel includes adhesive A and adhesive B, and the phosphor includes a first phosphor with a peak wavelength of 537 nm, a second phosphor with a peak wavelength of 558 nm, a third phosphor with a peak wavelength of 600 nm, and a fourth phosphor with a peak wavelength of 631 nm. The weight ratio of silica gel to phosphor is: adhesive A : adhesive B : first phosphor : second phosphor : third phosphor : fourth phosphor = (0.31-0.34) : (1.6-1.7) : (0.17-0.2)：(0.13-0.16)：(0.34-0.37)：(0.03-0.04)。 2. The LED light source for age-friendly lighting as described in claim 1, characterized in that, The first LED chip is a blue light chip with a peak wavelength of 450nm, and the second LED chip is a blue light chip with a peak wavelength of 455nm.

3. The LED light source for age-friendly lighting as described in claim 2, characterized in that, The chip area ratio of the first LED chip to the second LED chip is 1:1, and the peak spectral light power ratio of the first LED chip to the second LED chip is (0.85-0.9):(0.75-0.8).

4. The LED light source for age-friendly lighting as described in claim 1, characterized in that, The first phosphor is a green phosphor, the main component of which is Ga-YAG; the second phosphor is a yellow-green phosphor, the main component of which is YAG; the third phosphor is an orange-red phosphor, the main component of which is rare earth silicate; and the fourth phosphor is a red phosphor, the main component of which is tetravalent manganese activated potassium fluorosilicate.

5. The LED light source for age-friendly lighting as described in claim 1, characterized in that, The first LED chip and the second LED chip are fixed to the bottom of the bowl / cup with die bond adhesive.

6. The LED light source for age-friendly lighting as described in claim 5, characterized in that, The positive electrode of the first LED chip is connected to one of the conductive parts via a bonding wire, and the negative electrode of the second LED chip is connected to another conductive part via a bonding wire. The negative electrode of the first LED chip and the positive electrode of the second LED chip are connected to each other via bonding wires.

7. The LED light source for age-friendly lighting as described in claim 1, characterized in that, The bottom of the bracket has two metal electrodes for surface mounting, and the surface of the metal electrodes is tin-plated.

8. The LED light source for age-friendly lighting as described in claim 7, characterized in that, The surfaces of the two conductive parts are plated with silver, the two conductive parts are separated by an insulating part, and the two conductive parts are electrically connected to two metal electrodes respectively.

9. A method for preparing an age-friendly LED light source as described in any one of claims 1-8, characterized in that, It includes the following steps: Step 1: Apply die bond adhesive to the center of the bottom of the support cup, and place the first LED chip and the second LED chip on the die bond adhesive; Step 2: Place the chip-bearing bracket into a constant temperature chamber to cure the die-attach adhesive; the curing temperature is 150℃ and the curing time is 120 minutes, so that the chip is fixed on the bracket. Step 3: Using a wire bonding machine, the positive and negative electrodes of each chip are connected to the corresponding functional area on the support or the positive and negative electrodes of adjacent chips. Step 4: Prepare a fluorescent gel by mixing phosphor with silica gel. The phosphor is a mixture of green phosphor, yellow-green phosphor, orange-red phosphor, and red phosphor in a certain proportion. Step 5: Apply fluorescent adhesive to the bowl / cup, ensuring the fluorescent adhesive completely covers the functional area, chip, and bonding wires; Step 6: Place the bracket with the glue applied above into a constant temperature chamber for segmented curing. The curing conditions for the first segment are: curing temperature 100℃ and curing time 30 minutes. The second stage of curing conditions is a curing temperature of 130℃ and a curing time of 60 minutes. The third stage of curing conditions is a curing temperature of 150℃ and a curing time of 180 minutes. Step 7: Use an LED photoelectric parameter tester to test the photoelectric parameters of the finished LED, and finally obtain an LED light source suitable for elderly lighting.

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