Light emitting device, light emitting device control method, and manufacturing method

Abstract

This disclosure provides a light-emitting device, a control method for the light-emitting device, and a fabrication method. The light-emitting device includes: a substrate, a plurality of light-emitting diode (LED) chips, a reflective cavity, and a scattering colloid layer; the plurality of LED chips are all located on the substrate and are electrically connected to the substrate, and the plurality of LED chips include LED chips of multiple colors; the reflective cavity includes a first reflective cavity and a plurality of second reflective cavities, both of which are located on the substrate, and the plurality of second reflective cavities are all located within the cavity of the first reflective cavity, and the plurality of LED chips are respectively located within the cavities of the plurality of second reflective cavities; the scattering colloid layer is located within the cavity of the first reflective cavity, and the scattering colloid layer covers the plurality of LED chips, the plurality of second reflective cavities, and the substrate.

Description

Technical Field

[0001] This disclosure relates to the field of display technology, and in particular to a light-emitting device, a light-emitting device control method, and a preparation method. Background Technology

[0002] Light-emitting diode (LED) chips are widely used in lighting, display, and communication fields because of their high brightness, low power consumption, long lifespan, and fast response.

[0003] The related technology provides a light-emitting device, which includes a substrate, a plurality of light-emitting diode chips and a phosphor layer, wherein the plurality of light-emitting diode chips are located on the substrate and electrically connected to the substrate, and the phosphor layer covers the plurality of light-emitting diode chips.

[0004] However, the light-emitting devices with the above-mentioned structure have problems such as narrow color gamut, low color rendering, and inability to stably output white light. Summary of the Invention

[0005] This disclosure provides a light-emitting device, a control method for the light-emitting device, and a fabrication method, which can improve the color gamut and color rendering of the light-emitting device, enabling it to output stable white light. The technical solution is as follows: On one hand, a light-emitting device is provided, the light-emitting device comprising: Substrate, multiple light-emitting diode chips, reflective cavity, and scattering colloidal layer; The plurality of light-emitting diode chips are all located on the substrate and are all electrically connected to the substrate. The plurality of light-emitting diode chips include light-emitting diode chips of various colors. The reflective cavity includes a first reflective cavity and a plurality of second reflective cavities. The first reflective cavity and the second reflective cavities are both located on the substrate, and the plurality of second reflective cavities are all located within the cavity of the first reflective cavity. The plurality of light-emitting diode chips are respectively located within the cavities of the plurality of second reflective cavities. The scattering colloidal layer is located within the cavity of the first reflective cavity, and the scattering colloidal layer covers the plurality of light-emitting diode chips, the plurality of second reflective cavities, and the substrate.

[0006] Optionally, the plurality of light-emitting diode chips includes a red light-emitting diode chip, a green light-emitting diode chip, and a blue light-emitting diode chip; The reflecting cavity includes three second reflecting cavities, and the line connecting the centers of the three second reflecting cavities forms an equilateral triangle.

[0007] Optionally, the projection of the first reflective cavity onto the substrate surface is circular; The center of the equilateral triangle coincides with the center of the first reflective cavity.

[0008] Optionally, the scattering colloidal layer comprises: scattering particles and a transparent encapsulating adhesive; the scattering particles are dispersed within the transparent encapsulating adhesive.

[0009] Optionally, the scattering particles are nano zinc oxide particles, fumed silica particles, hollow silica particles, silicon nitride particles, or titanium dioxide particles.

[0010] Optionally, the light-emitting device further includes a photoelectric sensor; The photoelectric sensor is electrically connected to the substrate and is located in the gap between the plurality of second reflective cavities.

[0011] Optionally, the light-emitting device further includes a driving unit; The driving unit is electrically connected to the plurality of light-emitting diode chips and photoelectric sensors respectively; The driving unit is used to acquire the output electrical signal corresponding to the color parameters of the mixed light output by the light-emitting device detected by the photoelectric sensor; The driving unit is used to control the duty cycle or amplitude of the current of the light-emitting diode chip based on the output electrical signal.

[0012] On the other hand, a method for controlling a light-emitting device, the method comprising: the light-emitting device being the light-emitting device according to any one of claims 1 to 7, the method comprising: After the driving unit is initialized, the system of the driving unit acquires the target light color parameters and the initial driving parameters of each of the light-emitting diode chips; The driving unit outputs a driving current to control the light-emitting diode chip according to the initial driving parameters; The driving unit acquires the output electrical signal corresponding to the color parameters of the mixed light output by the light-emitting device detected by the photoelectric sensor; The driving unit obtains the color parameters of the mixed light output by the light-emitting device based on the output electrical signal, compares them with the target color parameters, and calculates the deviation value of the color parameters. The driving unit adjusts the duty cycle or amplitude of the output driving current based on the light color parameter deviation value.

[0013] In another aspect, a method for preparing a light-emitting device, the method comprising: Multiple light-emitting diode (LED) chips are electrically connected to a substrate, and the multiple LED chips include LED chips of various colors; A reflective cavity is fabricated on the substrate. The reflective cavity includes a first reflective cavity and a plurality of second reflective cavities. The first reflective cavity and the second reflective cavities are both located on the substrate, and the plurality of second reflective cavities are all located within the cavity of the first reflective cavity. The plurality of light-emitting diode chips are respectively located within the cavities of the plurality of second reflective cavities. A scattering colloidal layer is fabricated, which is located within the cavity of the first reflective cavity and covers the plurality of light-emitting diode chips, the plurality of second reflective cavities, and the substrate.

[0014] Optionally, the fabrication of the scattering colloidal layer includes: A scattering adhesive is made by mixing scattering particles with transparent encapsulating adhesive; The scattering adhesive is filled into the reflective cavity by spin coating. The scattering adhesive is cured by heating to form the scattering colloidal layer.

[0015] The beneficial effects of the technical solutions provided in this disclosure are: In this embodiment, multiple light-emitting diode (LED) chips are located on the substrate and electrically connected to it. These LED chips include LEDs of various colors. By mixing the light from these multiple colors, a phosphor layer is not required, enabling white light output. The reflective cavity includes a first reflective cavity and multiple second reflective cavities. Each second reflective cavity corresponds to a single LED chip and reflects the light emitted by the LED chip back to the light-emitting surface, effectively preventing lateral light leakage. Compared to related technologies that fabricate a reflective layer on the substrate, the sidewalls of the second reflective cavities reflect light into the cavity itself, allowing for thorough mixing and ensuring color uniformity on the light-emitting surface.

[0016] The multiple second reflection cavities are all located inside the first reflection cavity. The first reflection cavity can further mix the light emitted from the multiple second reflection cavities, thereby further improving the color uniformity of the surface.

[0017] The scattering colloidal layer is located inside the first reflection cavity and covers multiple light-emitting diode chips, multiple second reflection cavities, and a substrate. The light emitted by the light-emitting diode chips can be scattered multiple times inside the scattering colloidal layer, thereby achieving full mixing of light colors and ensuring the color uniformity of the light-emitting surface.

[0018] In summary, the light-emitting device provided in this embodiment of the present disclosure, through multiple second reflective cavities, a first reflective cavity, and a scattering colloid layer, enables the light emitted by multiple light-emitting diode chips to achieve sufficient mixing of light colors, ensuring the color uniformity of the light-emitting surface. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a top view of a light-emitting device provided in an embodiment of this disclosure; Figure 2 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure; Figure 3 This is a flowchart of the driving unit provided in an embodiment of this disclosure; Figure 4 This is a flowchart of a method for fabricating a light-emitting device according to an embodiment of this disclosure; Figure 5 This is a flowchart of a method for fabricating a light-emitting device according to an embodiment of this disclosure; Figure 6 This is a flowchart of a light-emitting device control method provided in an embodiment of this disclosure.

[0021] The attached figures are labeled as follows: 10: Substrate; 20: Light-emitting diode chip; 30: Reflective cavity; 40: Scattering colloidal layer; 50: Photoelectric sensor; 31: First reflecting cavity; 32: Second reflecting cavity. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.

[0023] Figure 1 This is a top view of a light-emitting device provided in an embodiment of this disclosure. Figure 2 This is a schematic diagram of the structure of a light-emitting device provided in an embodiment of this disclosure. See also... Figure 1 and Figure 2 , Figure 2 yes Figure 1 The cross-section of line A-A' is shown. The light-emitting device includes: a substrate 10, multiple light-emitting diode chips 20, a reflective cavity 30, and a scattering colloidal layer 40.

[0024] Multiple light-emitting diode chips 20 are located on the substrate 10 and are electrically connected to the substrate 10. The multiple light-emitting diode chips 20 include light-emitting diode chips of various colors.

[0025] The reflective cavity 30 includes a first reflective cavity 31 and a plurality of second reflective cavities 32. The first reflective cavity 31 and the second reflective cavity 32 are both located on the substrate 10, and the plurality of second reflective cavities 32 are all located inside the cavity of the first reflective cavity 31. The plurality of light-emitting diode chips 20 are respectively located inside the cavities of the plurality of second reflective cavities 32.

[0026] The scattering colloidal layer 40 is located inside the cavity of the first reflective cavity 31, and the scattering colloidal layer 40 covers multiple light-emitting diode chips 20, multiple second reflective cavities 32 and substrate 10.

[0027] In this embodiment, multiple light-emitting diode (LED) chips are located on the substrate and electrically connected to it. These LED chips include LEDs of various colors. By mixing the light from these multiple colors, a phosphor layer is not required, enabling white light output. The reflective cavity includes a first reflective cavity and multiple second reflective cavities. Each second reflective cavity corresponds to a single LED chip and reflects the light emitted by the LED chip back to the light-emitting surface, effectively preventing lateral light leakage. Compared to related technologies that fabricate a reflective layer on the substrate, the sidewalls of the second reflective cavities reflect light into the cavity itself, allowing for thorough mixing and ensuring color uniformity on the light-emitting surface.

[0028] The multiple second reflection cavities are all located inside the first reflection cavity. The first reflection cavity can further mix the light emitted from the multiple second reflection cavities, thereby further improving the color uniformity of the surface.

[0029] The scattering colloidal layer is located inside the first reflection cavity and covers multiple light-emitting diode chips, multiple second reflection cavities, and a substrate. The light emitted by the light-emitting diode chips can be scattered multiple times inside the scattering colloidal layer, thereby achieving full mixing of light colors and ensuring the color uniformity of the light-emitting surface.

[0030] In summary, the light-emitting device provided in this embodiment of the present disclosure, through multiple second reflective cavities, a first reflective cavity, and a scattering colloid layer, enables the light emitted by multiple light-emitting diode chips to achieve sufficient mixing of light colors, ensuring the color uniformity of the light-emitting surface.

[0031] In this embodiment of the disclosure, the substrate 10 may be a circuit board, and the substrate 10 may include a ceramic substrate, a metal substrate or a diamond substrate.

[0032] In this embodiment, the ceramic substrate can be an AlN substrate, a Si3N4 substrate, or a SiC substrate.

[0033] In this embodiment of the disclosure, the metal substrate may be an insulated metal substrate (IMS).

[0034] For example, substrate 10 is an AlN substrate.

[0035] In this embodiment of the disclosure, the substrate 10 further includes a driving circuit for driving the light-emitting diode (LED) chips 20. The driving circuit is used to drive multiple LED chips 20, enabling individual control of the multiple LED chips. That is, the driving circuit can control the circuit of one or more LED chips among the multiple LED chips to be turned on or off, and change the brightness of the LEDs by controlling the driving current.

[0036] In this embodiment of the disclosure, the plurality of light-emitting diode chips 20 includes a red light-emitting diode chip, a green light-emitting diode chip, and a blue light-emitting diode chip.

[0037] The reflecting cavity 30 includes three second reflecting cavities 32, and the line connecting the centers of the three second reflecting cavities 32 forms an equilateral triangle.

[0038] In this implementation, multiple LED chips include one red LED chip, one green LED chip, and one blue LED chip. Based on the color coordinates of the three basic colors (red, green, and blue), they form a triangle, which theoretically can cover all colors within this triangle. The color gamut range far exceeds that of related technologies that use LED chips with phosphors, achieving a color gamut greater than 100% of the National Television System Committee (NTSC) standard. By precisely controlling the proportions of the three colors, various spectral forms of white light can be simulated, easily achieving a Color Rendering Index (CRI) greater than 90, or even greater than 95, meeting the special lighting needs of museums, medical settings, and other applications. The reflective cavity includes three secondary reflective cavities, and the line connecting the centers of the three secondary reflective cavities forms an equilateral triangle, ensuring that the distance from any LED chip to the other two LED chips is equal, thus making the light color of the light-emitting device more uniform.

[0039] In other embodiments, the plurality of light-emitting diode chips 20 may also include other numbers of light-emitting diode chips. For example, the plurality of light-emitting diode chips 20 may include two red light-emitting diode chips, one green light-emitting diode chip, and one blue light-emitting diode chip.

[0040] In other embodiments, the reflective cavity 30 may also include other numbers of second reflective cavities 32, or the line connecting the centers of the multiple second reflective cavities 32 may have other shapes.

[0041] For example, the reflecting cavity 30 includes four second reflecting cavities 32, and the line connecting the centers of the four second reflecting cavities 32 forms a square.

[0042] In this embodiment of the disclosure, the light-emitting diode chip 20 can be a flip-chip light-emitting diode chip.

[0043] In this implementation, the flip chip has better thermal conductivity and light extraction efficiency.

[0044] In this embodiment of the disclosure, the peak wavelength of the red light-emitting diode chip is 610nm~630nm.

[0045] In this embodiment of the disclosure, the peak wavelength of the green light-emitting diode chip is 510nm~530nm.

[0046] In this embodiment of the disclosure, the peak wavelength of the blue light-emitting diode chip is 450nm~460nm.

[0047] In this embodiment of the disclosure, the first reflective cavity 31 and the second reflective cavity 32 can be plastic reflective cavities, high-reflectivity coated ceramic reflective cavities, metal reflective cavities, or high-reflectivity white wall adhesive reflective cavities.

[0048] The plastic can be encapsulated molding compound (EMC), sheet molding compound (SMC), poly(1,4-cyclohexylene dimethylene terephthalate) (PCT), polyphthalamide (PPA), etc.

[0049] High-reflectivity coated ceramics can include nano-ceramic materials and mirror coatings electroplated on the surface of nano-ceramic materials, with a reflectivity greater than 99%.

[0050] The metal may include a copper layer and a high-gloss silver layer electroplated on the surface of the copper layer, with a reflectivity greater than 98%.

[0051] High-reflectivity white wall adhesive can be a mixture of silicone and titanium dioxide.

[0052] For example, the first reflective cavity 31 and the second reflective cavity 32 are plastic reflective cavities.

[0053] In this embodiment of the disclosure, the projection of the surface of the substrate 10 of the first reflective cavity 31 is circular, and the center of the equilateral triangle coincides with the center of the circle of the first reflective cavity 31.

[0054] In this implementation, the projection of the first reflective cavity onto the substrate surface is circular, which makes the distance from the light emitted by the LED chip to all points on the sidewall of the first reflective cavity consistent, thereby making the light emitted by the LED chip more uniformly mixed in the reflective cavity and ensuring the color uniformity of the light-emitting surface of the light-emitting device; the center of the equilateral triangle coincides with the circle of the first reflective cavity, and the light is reflected through the inner wall of the first reflective cavity, reflecting the light emitted by the LED chip to the light-emitting surface, which can make the light color in the first reflective cavity more uniform.

[0055] In other embodiments, the projection onto the surface of the substrate 10 of the first reflective cavity 31 can also be other shapes, such as rectangles. When the projection onto the surface of the substrate 10 of the first reflective cavity 31 is a rectangle, the center of the rectangle coincides with the center of the first reflective cavity 31.

[0056] In this embodiment of the disclosure, the inner walls of the first reflecting cavity 31 and the second reflecting cavity 32 can be parabolic surfaces, inclined surfaces, or freeform surfaces.

[0057] For example, the inner walls of the first reflecting cavity 31 and the second reflecting cavity 32 are parabolic.

[0058] In other embodiments, the inner walls of the first reflecting cavity 31 and the second reflecting cavity 32 may also be irregular surfaces.

[0059] In this embodiment, the height of the second reflective cavity 32 in the direction perpendicular to the substrate is greater than the height of the light-emitting diode chip 20 in the direction perpendicular to the substrate, and the height of the first reflective cavity 31 in the direction perpendicular to the substrate is greater than the height of the second reflective cavity 32 in the direction perpendicular to the substrate.

[0060] In this implementation, the height of the second reflective cavity in the direction perpendicular to the substrate is greater than that of the LED chip in the direction perpendicular to the substrate, which can effectively prevent lateral light leakage from the LED chip; the height of the first reflective cavity in the direction perpendicular to the substrate is greater than that of the second reflective cavity in the direction perpendicular to the substrate, which allows the scattering colloid layer to completely cover the second reflective cavity, so that the light emitted by the LED chip can be scattered in the scattering colloid layer instead of directly entering the air, thereby ensuring the color uniformity of the light-emitting surface.

[0061] In other embodiments, the height of the second reflective cavity 32 in the direction perpendicular to the substrate is equal to the height of the light-emitting diode chip 20 in the direction perpendicular to the substrate, and the height of the first reflective cavity 31 in the direction perpendicular to the substrate is equal to the height of the second reflective cavity 32 in the direction perpendicular to the substrate.

[0062] In this embodiment of the disclosure, the scattering colloidal layer 40 includes scattering particles and a transparent encapsulating adhesive, wherein the scattering particles are dispersed within the transparent encapsulating adhesive.

[0063] In this implementation, the scattering particles can cause the three colors of light to be scattered multiple times inside the transparent encapsulating adhesive, thereby achieving full mixing of light colors and ensuring the color uniformity of the light-emitting surface; the transparent encapsulating adhesive can provide support for the scattering particles.

[0064] In other embodiments, the scattering particles in the scattering colloidal layer 40 may also be concentrated within the transparent encapsulating adhesive. For example, the scattering particles may be concentrated at the bottom of the transparent encapsulating adhesive.

[0065] In this embodiment of the disclosure, the scattering particles may be nano zinc oxide particles, fumed silica particles, hollow silica particles, silicon nitride particles, or titanium dioxide particles.

[0066] In this implementation, nano zinc oxide particles, fumed silica particles, hollow silica particles, silicon nitride particles, or titanium dioxide particles all have high scattering efficiency and excellent scattering effect in the visible light band, thereby making the light color mixing of the light-emitting device more uniform.

[0067] For example, the scattering particles are nano-zinc oxide particles.

[0068] In this embodiment of the disclosure, the transparent encapsulant can be an epoxy resin encapsulant, a silicone resin encapsulant, an organosilicon polymer encapsulant, or a polyurethane encapsulant.

[0069] For example, the transparent encapsulant is an epoxy resin encapsulant.

[0070] In this embodiment of the disclosure, the light-emitting device further includes a photoelectric sensor 50.

[0071] The photoelectric sensor 50 is electrically connected to the substrate 10, and the photoelectric sensor 50 is located in the gap between the plurality of second reflective cavities 32.

[0072] In this implementation, the photoelectric sensor is electrically connected to the substrate and is located in the gap between multiple second reflective cavities. It can be used to detect the light color parameters of the light-emitting device in real time and convert the light color parameters into an output electrical signal. The light color parameters are the color temperature and brightness of the light.

[0073] In this embodiment of the disclosure, the photoelectric sensor 50 may be a photodiode, a phototransistor, a photoresistor, a fiber optic photoelectric sensor, a color sensor, or a spectral sensor, etc.

[0074] For example, the photoelectric sensor 50 is a photodiode.

[0075] The photoelectric sensor 50 is located at the center of the equilateral triangle formed by the lines connecting the centers of the three second reflective cavities 32.

[0076] In this embodiment of the present disclosure, the light-emitting device further includes a driving unit.

[0077] The driving unit is electrically connected to multiple light-emitting diode chips 20 and photoelectric sensors 50, respectively.

[0078] The driving unit is used to acquire the output electrical signal corresponding to the color parameters of the mixed light output by the light-emitting device detected by the photoelectric sensor 50.

[0079] The driving unit is used to control the duty cycle or amplitude of the current of the light-emitting diode chip 20 based on the output electrical signal.

[0080] In this implementation, the color deviation of the light-emitting device is monitored by a photoelectric sensor, and the light color parameters of the light-emitting diode chip are controlled in real time by a driving unit. This effectively overcomes the problems of temperature drift and aging, and ensures the high stability of the light color throughout the lifespan of the light-emitting device.

[0081] Figure 3 This is a flowchart of the driving unit provided in an embodiment of this disclosure. See also... Figure 3 The drive unit receives externally set target light color commands (such as correlated color temperature (CCT), brightness, xy coordinates) and real-time data fed back by photoelectric sensor 50. Through internal algorithms (such as proportional-integral-derivative (PID) control algorithms), it independently adjusts the pulse width modulation (PWM) current or constant current source magnitude output to multiple light-emitting diode chips 20 to achieve closed-loop feedback control.

[0082] In this implementation, the drive unit can receive instructions through a digital interface and be easily integrated into a smart lighting system to achieve scene-based and programmable dynamic lighting effects.

[0083] For example, when the photoelectric sensor 50 detects that the light color of the light-emitting device deviates from the target light color, the photoelectric sensor 50 feeds back the output electrical signal to the driving unit. The driving unit compares the output electrical signal with the target light color parameter, calculates the light color parameter deviation value, and dynamically adjusts the duty cycle or amplitude of the output driving current based on the light color parameter deviation value to control the light color parameter of the light-emitting diode chip 20, so as to make the light color parameter of the light-emitting device consistent with the target light color parameter.

[0084] For example, if any of the light color parameters corresponding to the output electrical signal is larger than any of the target light color parameters, and the difference is within a first set range, then the duty cycle decreases by 0-2%, and / or the amplitude decreases by 0-0.5%. In the above control, the larger the difference, the greater the corresponding reduction ratio. If any of the light color parameters corresponding to the output electrical signal is smaller than any of the target light color parameters, and the difference is within a first set range, then the duty cycle increases by 0-2%, and / or the amplitude increases by 0-0.5%. In the above control, the larger the difference, the greater the corresponding increase ratio.

[0085] The first set range can be a proportional value, such as greater than 0% and not greater than 0.01%.

[0086] Alternatively, the first set range can be a numerical value, such as a color temperature difference greater than 0 and not greater than 0.01K; or a brightness difference greater than 0 and not greater than 0.01nit.

[0087] If any of the light color parameters corresponding to the output electrical signal is larger than any of the target light color parameters, and the difference is within the second set range, then the duty cycle decreases by 0-5%, and / or the amplitude decreases by 0-1%. In the above control, the larger the difference, the larger the corresponding reduction ratio. If any of the light color parameters corresponding to the output electrical signal is smaller than any of the target light color parameters, and the difference is within the second set range, then the duty cycle increases by 0-5%, and / or the amplitude increases by 0-1%. In the above control, the larger the difference, the larger the corresponding increase ratio.

[0088] The second set range can be a percentage value, for example, greater than 0% and not greater than 0.02%.

[0089] Alternatively, the second set range can be a numerical value, such as a color temperature difference greater than 0 and not greater than 0.02K; or a brightness difference greater than 0 and not greater than 0.02nit.

[0090] If any of the light color parameters corresponding to the output electrical signal is greater than any of the target light color parameters, and the difference is within the third set range, the duty cycle decreases by 0-8%, and / or the amplitude decreases by 0-2%. In the above control, the larger the difference, the greater the corresponding reduction ratio. If any of the light color parameters corresponding to the output electrical signal is smaller than any of the target light color parameters, and the difference is within the third set range, the duty cycle increases by 0-8%, and / or the amplitude increases by 0-2%. In the above control, the larger the difference, the greater the corresponding increase ratio.

[0091] The third set range can be a percentage value, such as greater than 0% and not greater than 0.03%.

[0092] Alternatively, the third setting range can be a numerical value, such as a color temperature difference greater than 0 and not greater than 0.03K; or a brightness difference greater than 0 and not greater than 0.03nit.

[0093] Furthermore, the above control can be applied to multiple LED chips simultaneously. In some examples, the color of the LED chip to be controlled can be determined based on color deviation, and then the above control can be applied to one of the LED chips of a specific color.

[0094] Figure 4 This is a flowchart illustrating a method for fabricating a light-emitting device according to an embodiment of this disclosure. See also... Figure 4 The method includes the following steps: S11. Electrically connect multiple light-emitting diode chips to a substrate, wherein the multiple light-emitting diode chips include light-emitting diode chips of various colors.

[0095] In this embodiment of the disclosure, the substrate may be a ceramic substrate, a metal substrate, or a diamond substrate.

[0096] In this implementation, the ceramic substrate, metal substrate, or diamond substrate has good insulation and thermal conductivity, which is beneficial for heat dissipation of the light-emitting device.

[0097] In this embodiment, the ceramic substrate can be an AlN substrate, a Si3N4 substrate, or a SiC substrate.

[0098] In this embodiment of the disclosure, the metal substrate may be an IMS substrate.

[0099] For example, the substrate is an AlN substrate.

[0100] In this embodiment of the disclosure, the light-emitting diode chip can be a flip-chip light-emitting diode chip.

[0101] S12. A reflective cavity is fabricated on the substrate. The reflective cavity includes a first reflective cavity and a plurality of second reflective cavities. The first reflective cavity and the second reflective cavities are both located on the substrate, and the plurality of second reflective cavities are all located within the cavity of the first reflective cavity. The plurality of light-emitting diode chips are respectively located within the cavities of the plurality of second reflective cavities.

[0102] In this embodiment of the disclosure, the first reflective cavity and the second reflective cavity can be plastic reflective cavity, high-reflectivity coated ceramic reflective cavity, metal reflective cavity or high-reflectivity white wall adhesive reflective cavity.

[0103] The plastic can be materials such as EMC, SMC, PCT, and PPA.

[0104] High-reflectivity coated ceramics can include nano-ceramic materials and mirror coatings electroplated on the surface of nano-ceramic materials, with a reflectivity greater than 99%.

[0105] The metal may include a copper layer and a high-gloss silver layer electroplated on the surface of the copper layer, with a reflectivity greater than 98%.

[0106] High-reflectivity white wall adhesive can be a mixture of silicone and titanium dioxide.

[0107] For example, the first and second reflective cavities are plastic reflective cavities.

[0108] S13. Fabricate a scattering colloidal layer, wherein the scattering colloidal layer is located within the cavity of the first reflective cavity, and the scattering colloidal layer covers the plurality of light-emitting diode chips, the plurality of second reflective cavities, and the substrate.

[0109] In this embodiment of the disclosure, the scattering colloidal layer includes scattering particles and a transparent encapsulating adhesive, wherein the scattering particles are dispersed within the transparent encapsulating adhesive.

[0110] In this embodiment, multiple light-emitting diode (LED) chips are located on the substrate and electrically connected to it. These LED chips include LEDs of various colors. By mixing the light from these multiple colors, white light output can be achieved without the need for a phosphor layer. The reflective cavity includes a first reflective cavity and multiple second reflective cavities, both located on the substrate. The second reflective cavities reflect the light emitted by the LEDs, directing it to the light-emitting surface, effectively preventing lateral light leakage. Compared to related technologies that fabricate a reflective layer on the substrate, the sidewalls of the second reflective cavities reflect light into their cavity, allowing for thorough mixing and ensuring color uniformity at the light-emitting surface. Furthermore, the multiple second reflective cavities are located within the first reflective cavity, further mixing the light emitted from the second reflective cavities. This further improves the color uniformity of the light-emitting surface. Multiple LED chips are located within multiple second reflective cavities, and a scattering colloid layer is located within the first reflective cavity. The scattering colloid layer covers the multiple LED chips, multiple second reflective cavities, and the substrate. The light emitted by the LED chips can be scattered multiple times within the scattering colloid layer, thereby achieving sufficient color mixing and ensuring the color uniformity of the light-emitting surface. In summary, the light-emitting device provided in this application initially mixes the light emitted by the LED chips within the cavities using multiple second reflective cavities, improving the color uniformity of the light emitted by the LED chips. Then, the first reflective cavity further mixes the light emitted by the multiple LED chips, further improving the color uniformity of the light-emitting surface. Finally, by setting a scattering colloid layer, the light emitted by the LED chips can be scattered multiple times within the scattering colloid layer, thereby achieving sufficient color mixing and ensuring the color uniformity of the light-emitting surface.

[0111] Figure 5 This is a flowchart illustrating a method for fabricating a light-emitting device according to an embodiment of this disclosure. See also... Figure 5 The method includes the following steps: S21. Electrically connect multiple light-emitting diode chips to the substrate, wherein the multiple light-emitting diode chips include light-emitting diode chips of various colors.

[0112] In this process, multiple light-emitting diode chips are fixed on the substrate by sintering using eutectic or nano-silver paste.

[0113] In this embodiment of the disclosure, the substrate may be a circuit board, and the substrate may include a ceramic substrate, a metal substrate, or a diamond substrate.

[0114] In this implementation, the ceramic substrate, metal substrate, or diamond substrate has good insulation and thermal conductivity, which is beneficial for heat dissipation of the light-emitting device.

[0115] In this embodiment, the ceramic substrate can be an AlN substrate, a Si3N4 substrate, or a SiC substrate.

[0116] In this embodiment of the disclosure, the metal substrate may be an IMS substrate.

[0117] For example, the substrate is an AlN substrate.

[0118] In this embodiment of the disclosure, the substrate further includes a driving circuit for driving the light-emitting diode (LED) chips. The driving circuit is used to drive multiple LED chips, enabling individual control of the multiple LED chips. That is, the driving circuit can control the circuit of one or more LED chips to be turned on or off, and change the brightness of the LEDs by controlling the driving current.

[0119] In this embodiment of the disclosure, the plurality of light-emitting diode chips includes a red light-emitting diode chip, a green light-emitting diode chip, and a blue light-emitting diode chip.

[0120] In this implementation, multiple LED chips, including a red LED chip, a green LED chip, and a blue LED chip, are arranged in a triangle based on the color coordinates of the three basic colors: red, green, and blue. Theoretically, this triangle can cover all colors within it, resulting in a color gamut far exceeding that of LED chips with phosphors in related technologies. It can achieve a color gamut greater than 100% of the National Television System Committee (NTSC) standard. By precisely controlling the proportions of the three colors, it can simulate white light in various spectral forms, easily achieving a Color Rendering Index (CRI) greater than 90, or even greater than 95, meeting the special lighting needs of museums, medical facilities, and other applications.

[0121] In other embodiments, the plurality of light-emitting diode (LED) chips may also include other numbers of LED chips. For example, the plurality of LED chips may include two red LED chips, one green LED chip, and one blue LED chip.

[0122] In this embodiment of the disclosure, the light-emitting diode chip can be a flip-chip light-emitting diode chip.

[0123] In this implementation, the flip chip has better thermal conductivity and light extraction efficiency.

[0124] In this embodiment of the disclosure, the peak wavelength of the red light-emitting diode chip is 610nm~630nm.

[0125] In this embodiment of the disclosure, the peak wavelength of the green light-emitting diode chip is 510nm~530nm.

[0126] In this embodiment of the disclosure, the peak wavelength of the blue light-emitting diode chip is 450nm~460nm.

[0127] S22. A reflective cavity is fabricated on a substrate. The reflective cavity includes a first reflective cavity and a plurality of second reflective cavities. Both the first and second reflective cavities are located on the substrate, and the plurality of second reflective cavities are located within the cavity of the first reflective cavity. A plurality of light-emitting diode chips are respectively located within the cavities of the plurality of second reflective cavities.

[0128] In the embodiments disclosed herein, the reflective cavity is fabricated by means of injection molding, stamping, machining, electroplating or laser processing.

[0129] For example, the reflective cavity is fabricated by injection molding.

[0130] In this embodiment of the disclosure, the first reflective cavity and the second reflective cavity can be plastic reflective cavity, high-reflectivity coated ceramic reflective cavity, metal reflective cavity or high-reflectivity white wall adhesive reflective cavity.

[0131] The plastic can be materials such as EMC, SMC, PCT, and PPA.

[0132] High-reflectivity coated ceramics can include nano-ceramic materials and mirror coatings electroplated on the surface of nano-ceramic materials, with a reflectivity greater than 99%.

[0133] The metal may include a copper layer and a high-gloss silver layer electroplated on the surface of the copper layer, with a reflectivity greater than 98%.

[0134] High-reflectivity white wall adhesive can be a mixture of silicone and titanium dioxide.

[0135] For example, the first and second reflective cavities are plastic reflective cavities.

[0136] In this embodiment of the present disclosure, the reflecting cavity includes three second reflecting cavities, and the line connecting the centers of the three second reflecting cavities forms an equilateral triangle.

[0137] In this implementation, the reflective cavity includes three second reflective cavities, and the line connecting the centers of the three second reflective cavities forms an equilateral triangle, so that the distance from any one LED chip to the other two LED chips is equal, thereby making the light color of the light-emitting device more uniform.

[0138] In other embodiments, the reflecting cavity may also include other numbers of second reflecting cavities, or the line connecting the centers of the multiple second reflecting cavities may have other shapes.

[0139] For example, the reflecting cavity includes four second reflecting cavities, and the line connecting the centers of the four second reflecting cavities forms a square.

[0140] In this embodiment of the disclosure, the projection of the surface of the first reflective cavity substrate is circular, and the center of the equilateral triangle coincides with the center of the first reflective cavity.

[0141] In this implementation, the projection of the first reflective cavity onto the substrate surface is circular, which makes the distance from the light emitted by the LED chip to all points on the sidewall of the first reflective cavity consistent, thereby making the light emitted by the LED chip more uniformly mixed in the reflective cavity and ensuring the color uniformity of the light-emitting surface of the light-emitting device; the center of the equilateral triangle coincides with the circle of the first reflective cavity, and the light is reflected through the inner wall of the first reflective cavity, reflecting the light emitted by the LED chip to the light-emitting surface, which can make the light color in the first reflective cavity more uniform.

[0142] In other embodiments, the projection onto the surface of the first reflective cavity substrate can also be other shapes, such as a rectangle. When the projection onto the surface of the first reflective cavity substrate is a rectangle, the center of the rectangle coincides with the center of the first reflective cavity.

[0143] In the embodiments of this disclosure, the inner walls of the first and second reflecting cavities can be parabolic surfaces, inclined surfaces, or freeform surfaces.

[0144] For example, the inner walls of the first and second reflecting cavities are parabolic.

[0145] In other embodiments, the inner walls of the first and second reflecting cavities may also be irregular surfaces.

[0146] In this embodiment of the disclosure, the height of the second reflective cavity in the direction perpendicular to the substrate is greater than the height of the light-emitting diode chip in the direction perpendicular to the substrate, and the height of the first reflective cavity in the direction perpendicular to the substrate is greater than the height of the second reflective cavity in the direction perpendicular to the substrate.

[0147] In this implementation, the height of the second reflective cavity in the direction perpendicular to the substrate is greater than that of the LED chip in the direction perpendicular to the substrate, which can effectively prevent lateral light leakage from the LED chip; the height of the first reflective cavity in the direction perpendicular to the substrate is greater than that of the second reflective cavity in the direction perpendicular to the substrate, which allows the scattering colloid layer to completely cover the second reflective cavity, so that the light emitted by the LED chip can be scattered in the scattering colloid layer instead of directly entering the air, thereby ensuring the color uniformity of the light-emitting surface.

[0148] In other embodiments, the height of the second reflective cavity in the direction perpendicular to the substrate is equal to the height of the light-emitting diode chip in the direction perpendicular to the substrate, and the height of the first reflective cavity in the direction perpendicular to the substrate is equal to the height of the second reflective cavity in the direction perpendicular to the substrate.

[0149] S23. Fabricate a scattering colloidal layer, which is located inside the cavity of the first reflective cavity and covers multiple light-emitting diode chips, multiple second reflective cavities, and a substrate.

[0150] For example, step S23 may include: The first step is to mix the scattering particles and the transparent encapsulating adhesive to make the scattering adhesive.

[0151] In this embodiment of the disclosure, the scattering colloidal layer includes scattering particles and a transparent encapsulating adhesive, wherein the scattering particles are dispersed within the transparent encapsulating adhesive.

[0152] In this implementation, the scattering particles can cause the three colors of light to be scattered multiple times inside the transparent encapsulating adhesive, thereby achieving full mixing of light colors and ensuring the color uniformity of the light-emitting surface; the transparent encapsulating adhesive can provide support for the scattering particles.

[0153] In other embodiments, the scattering particles in the scattering colloidal layer may also be concentrated within the transparent encapsulating adhesive. For example, the scattering particles may be concentrated at the bottom of the transparent encapsulating adhesive.

[0154] In this embodiment of the disclosure, the scattering particles may be nano zinc oxide particles, fumed silica particles, hollow silica particles, silicon nitride particles, or titanium dioxide particles.

[0155] In this implementation, nano zinc oxide particles, fumed silica particles, hollow silica particles, silicon nitride particles, or titanium dioxide particles all have high scattering efficiency and excellent scattering effect in the visible light band, thereby making the light color mixing of the light-emitting device more uniform.

[0156] For example, the scattering particles are nano-zinc oxide particles.

[0157] In this embodiment of the disclosure, the transparent encapsulant can be an epoxy resin encapsulant, a silicone resin encapsulant, an organosilicon polymer encapsulant, or a polyurethane encapsulant.

[0158] For example, the transparent encapsulant is an epoxy resin encapsulant.

[0159] The second step is to fill the reflective cavity with the scattering adhesive using a spin coating method.

[0160] The third step is to form a scattering colloidal layer by heating and curing the scattering adhesive.

[0161] In this embodiment of the present disclosure, the scattering adhesive is heated at a temperature of 120~170°C for 1~5 hours to form a scattering colloidal layer.

[0162] For example, the scattering adhesive is heated at 150°C for 3 hours to form a scattering colloidal layer.

[0163] In another embodiment, the sample is first heated at a temperature of 60-100°C for 0.5-1 hour, and then heated at a temperature of 120-150°C for 1-4 hours.

[0164] For example, the material is first heated at 80°C for 0.8 hours, and then heated at 140°C for 2 hours.

[0165] S24. Electrically connect the photoelectric sensor to the substrate. The photoelectric sensor is located in the gap between multiple second reflective cavities.

[0166] In this implementation, the photoelectric sensor is electrically connected to the substrate and is located in the gap between multiple second reflective cavities. It can be used to detect the light color parameters of the light-emitting device in real time and convert the light color parameters into an output electrical signal. The light color parameters are the color temperature and brightness of the light.

[0167] In this embodiment of the disclosure, the photoelectric sensor is electrically connected to the substrate via standard wiring terminals or soldering.

[0168] For example, the photoelectric sensor is electrically connected to the substrate using standard wiring terminals.

[0169] Figure 6 This is a flowchart of a light-emitting device control method provided in an embodiment of this disclosure. See also... Figure 6 The steps of this method include: S31. After the drive unit is initialized, the drive unit system acquires the target light color parameters and the initial drive parameters of each light-emitting diode chip.

[0170] In this embodiment of the disclosure, the light color parameters may include color temperature and brightness.

[0171] In this implementation, the target light color parameters and the initial driving parameters of each LED chip can be written through other devices.

[0172] S32, the driving unit outputs driving current to control the light-emitting diode chips according to the initial driving parameters.

[0173] For example, if the initial driving parameters of each LED chip are different, the driving unit will output different driving currents to each LED chip to achieve independent control.

[0174] S33. The driving unit acquires the output electrical signal corresponding to the color parameters of the mixed light output by the light-emitting device detected by the photoelectric sensor.

[0175] S34. The driving unit obtains the color parameters of the mixed light output by the light-emitting device based on the electrical signal, compares them with the target color parameters, and calculates the deviation value of the color parameters.

[0176] For example, if the driving unit detects a difference between the color parameters of the mixed light output by the light-emitting device and the target color parameters based on the electrical signal, the driving unit will subtract the color parameters of the mixed light output by the light-emitting device from the target color parameters to obtain the deviation value of the color parameters.

[0177] S35. The drive unit adjusts the duty cycle or amplitude of the output drive current based on the light color parameter deviation value.

[0178] The goal is to control the color parameters of the light-emitting diode chip to achieve the target color parameters.

[0179] For example, if the deviation value of the light color parameter obtained by the driving unit indicates that the mixed light color of each light-emitting diode chip is different from the target light color parameter, then the duty cycle or amplitude of the output driving current is adjusted to make the light color parameter of the light-emitting device consistent with the target light color parameter or within the preset range.

[0180] S36. Repeat steps S33 to S36 to ensure that the light color parameters of the light-emitting device are consistent with the target light color parameters or within the preset range.

[0181] In this implementation, the color deviation of the light-emitting device is monitored by a photoelectric sensor, and the light color parameters of the light-emitting diode chip are controlled in real time by a driving unit. This effectively overcomes the problems of temperature drift and aging, and ensures the high stability of the light color throughout the lifespan of the light-emitting device.

[0182] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A light-emitting device, characterized in that, The light-emitting device includes: a substrate (10), a plurality of light-emitting diode chips (20), a reflective cavity (30), and a scattering colloidal layer (40). The plurality of light-emitting diode chips (20) are all located on the substrate (10) and are all electrically connected to the substrate (10). The plurality of light-emitting diode chips (20) include light-emitting diode chips of various colors. The reflective cavity (30) includes a first reflective cavity (31) and a plurality of second reflective cavities (32). The first reflective cavity (31) and the second reflective cavity (32) are both located on the substrate (10), and the plurality of second reflective cavities (32) are all located inside the cavity of the first reflective cavity (31). The plurality of light-emitting diode chips (20) are respectively located inside the cavities of the plurality of second reflective cavities (32). The scattering colloidal layer (40) is located inside the cavity of the first reflective cavity (31), and the scattering colloidal layer (40) covers the plurality of light-emitting diode chips (20), the plurality of second reflective cavities (32) and the substrate (10).

2. The light-emitting device according to claim 1, characterized in that, The plurality of light-emitting diode chips (20) includes a red light-emitting diode chip, a green light-emitting diode chip and a blue light-emitting diode chip; The reflective cavity (30) includes three second reflective cavities (32), and the line connecting the centers of the three second reflective cavities (32) forms an equilateral triangle.

3. The light-emitting device according to claim 2, characterized in that, The projection of the first reflective cavity (31) onto the surface of the substrate (10) is circular; The center of the equilateral triangle coincides with the center of the first reflective cavity (31).

4. The light-emitting device according to any one of claims 1 to 3, characterized in that, The scattering colloidal layer (40) includes: scattering particles and transparent encapsulating adhesive; the scattering particles are dispersed within the transparent encapsulating adhesive.

5. The light-emitting device according to claim 4, characterized in that, The scattering particles are nano zinc oxide particles, fumed silica particles, hollow silica particles, silicon nitride particles, or titanium dioxide particles.

6. The light-emitting device according to any one of claims 1 to 3, characterized in that, The light-emitting device also includes a photoelectric sensor (50). The photoelectric sensor (50) is electrically connected to the substrate (10), and the photoelectric sensor (50) is located in the gap between the plurality of second reflective cavities (32).

7. The light-emitting device according to any one of claims 1 to 3, characterized in that, The light-emitting device also includes a driving unit; The driving unit is electrically connected to a plurality of the light-emitting diode chips (20) and photoelectric sensors (50); The driving unit is used to acquire the output electrical signal corresponding to the color parameters of the mixed light output by the light-emitting device detected by the photoelectric sensor (50); The driving unit is used to control the duty cycle or amplitude of the current of the light-emitting diode chip (20) based on the output electrical signal.

8. A method for controlling a light-emitting device, characterized in that, The light-emitting device is the light-emitting device according to any one of claims 1 to 7, and the method includes: After the driving unit is initialized, the system of the driving unit acquires the target light color parameters and the initial driving parameters of each of the light-emitting diode chips; The driving unit outputs a driving current to control the light-emitting diode chip according to the initial driving parameters; The driving unit acquires the output electrical signal corresponding to the color parameters of the mixed light output by the light-emitting device detected by the photoelectric sensor; The driving unit obtains the color parameters of the mixed light output by the light-emitting device based on the output electrical signal, compares them with the target color parameters, and calculates the deviation value of the color parameters. The driving unit adjusts the duty cycle or amplitude of the output driving current based on the light color parameter deviation value.

9. A method for preparing a light-emitting device, characterized in that, The method includes: Multiple light-emitting diode (LED) chips are electrically connected to a substrate, and the multiple LED chips include LED chips of various colors; A reflective cavity is fabricated on the substrate. The reflective cavity includes a first reflective cavity and a plurality of second reflective cavities. The first reflective cavity and the second reflective cavities are both located on the substrate, and the plurality of second reflective cavities are all located within the cavity of the first reflective cavity. The plurality of light-emitting diode chips are respectively located within the cavities of the plurality of second reflective cavities. A scattering colloidal layer is fabricated, which is located within the cavity of the first reflective cavity and covers the plurality of light-emitting diode chips, the plurality of second reflective cavities, and the substrate.

10. The method according to claim 9, characterized in that, The fabrication of the scattering colloidal layer includes: A scattering adhesive is made by mixing scattering particles with transparent encapsulating adhesive; The scattering adhesive is filled into the reflective cavity by spin coating. The scattering adhesive is cured by heating to form the scattering colloidal layer.

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