A multi-channel LED light source module

Abstract

The utility model provides a kind of multi-channel LED light source module, including substrate, the substrate has insulating heat conduction body and be arranged on its circuit wiring;Multiple independent light emitting units are mounted on the same mounting plane of the substrate along an arrangement direction, and are electrically connected with the circuit wiring respectively;Wherein, at least two independent light emitting units are configured to emit light of different center wavelengths;Encapsulant is formed by light-transmitting material, covers all the independent light emitting units;Wherein, the first optical cavity and the second optical cavity that are different in axial height are formed in the encapsulant;The first optical cavity covers at least two independent light emitting units located at both ends of the arrangement direction, the second optical cavity covers at least one independent light emitting unit located in the middle of the arrangement direction, and at least one inner side wall of the first optical cavity is inclined light guide wall towards the second optical cavity, improves light mixing uniformity.

Description

Technical Field

[0001] This utility model relates to the field of LED light source technology, and in particular to a multi-channel LED light source module. Background Technology

[0002] With the rapid development of intelligent lighting, high-end displays, and special light sources, the market has placed unprecedented demands on the optical performance of LED light sources. Multi-channel LED light source modules, especially COB (Chip-on-Board) packaged devices that can independently control red (R), green (G), blue (B), and white light (W) at different color temperatures, have become core light source components for film and television shooting, stage lighting, architectural landscaping, and high-end commercial lighting due to their ability to achieve full color adjustment, high color rendering index, and dynamic white light color temperature.

[0003] Currently, the mainstream technologies for achieving multispectral COB packaging fall into two main categories. The first category employs a planar array of multiple monochrome chips (such as RGB) covered with a common phosphor conversion layer or individually coated with phosphor adhesive. While this approach is relatively simple in structure, the spatial separation of the light-emitting centers of different color chips leads to severe color spots and color overlap on the light-emitting surface. To achieve uniform light mixing, it is usually necessary to sacrifice the compactness of the packaging structure, setting a longer mixing distance (typically greater than 5mm), or relying on complex external optical lenses for secondary optical processing. This undoubtedly increases the overall size and design complexity of the luminaire.

[0004] The second type of technology aims to improve integration by integrating both conventional and flip-chip chips on the same substrate to optimize electrical and thermal performance. However, conventional chips (usually connected by gold wire bonding) and flip-chip chips (connected by solder bumps) have an inherent physical height difference. In traditional packaging concepts, this height difference is considered a process inconsistency defect that needs to be overcome. Conventional packaging methods use a large amount of encapsulating colloid for filling and leveling, forming a planar or arched encapsulation layer of uniform thickness. While this method achieves a smooth surface, it completely ignores the differences in light emission characteristics of chips at different locations. This results in insufficient spatial convergence between the light emitted by chips located at the edge of the module (usually flip-chips) and the light emitted by chips in the central area (usually conventional chips), forming a "halo" or "color layering" phenomenon in the near-field region, which seriously affects the spatial color uniformity (SCU) of the light source.

[0005] In summary, existing multi-channel COB packaging technologies, in pursuing high-density, multi-spectral integration, generally face a fundamental contradiction between "light mixing uniformity" and "structural compactness." They must either sacrifice size and cost for uniformity or tolerate poor optical performance within a compact structure. Especially when chips with different interconnection methods are used in combination, their inherent height differences are not effectively utilized, instead becoming a bottleneck restricting further improvements in optical performance. Utility Model Content

[0006] Therefore, the purpose of this utility model is to provide a multi-channel LED light source module to solve the problems mentioned above in the background technology.

[0007] A multi-channel LED light source module includes a substrate, the substrate having an insulating and thermally conductive body and circuit wiring disposed thereon;

[0008] Multiple independent light-emitting units are mounted on the same mounting plane of the substrate along an arrangement direction and are electrically connected to the circuit wiring respectively; wherein at least two of the independent light-emitting units are configured to emit light with different center wavelengths;

[0009] An encapsulation body, formed of a light-transmitting material, covers all the individual light-emitting units; wherein, a first optical cavity and a second optical cavity with different axial heights are formed within the encapsulation body; the first optical cavity covers at least two of the individual light-emitting units located at both ends of the arrangement direction, and the second optical cavity covers at least one of the individual light-emitting units located in the middle of the arrangement direction; wherein, the axial height of the first optical cavity is less than the axial height of the second optical cavity, and at least one inner sidewall of the first optical cavity is a light guide wall inclined toward the second optical cavity.

[0010] Compared to existing technologies, the advantages of this application are as follows: It improves light mixing uniformity through an asymmetric optical cavity structure with varying axial heights and inclined light guide walls formed within the package. Specifically, the first optical cavity located on both sides and its inclined light guide walls actively refract and guide large-angle light emitted from the edge chip to the central region of the module. The deeper second optical cavity located in the center and its vertical reflective wall provide ample space for cross-mixing of light from the central chip and reflect lateral light back to the mixing area. This synergistic effect allows light of different positions and colors to be efficiently and forcibly mixed within the package (typically within an extremely short distance of less than 2 mm), fundamentally eliminating color spots and color layering, achieving excellent spatial color uniformity (SCU) on the light-emitting surface, and allowing for exceptionally compact luminaire designs without relying on complex external light mixing structures or long optical paths.

[0011] Furthermore, it also includes a first type of connecting part and a second type of connecting part;

[0012] The independent light-emitting units located at both ends of the arrangement direction are electrically connected to the circuit wiring through the first type of connection part, and the first type of connection part is a conductive bump.

[0013] The independent light-emitting unit located in the middle of the arrangement direction is electrically connected to the circuit wiring through the second type of connection part, which is a bonding wire.

[0014] Furthermore, at least one conductive pad is provided on the insulating and heat-conducting body, the conductive pad constitutes the circuit wiring and is electrically connected to the first type of connection part;

[0015] The insulating and thermally conductive body forms at least one thermally conductive area in the region outside the conductive pad.

[0016] The heat-conducting area covers multiple independent light-emitting units in the vertical projection and is electrically insulated from the conductive pads.

[0017] Furthermore, the heat-conducting region includes a first heat-conducting zone and a second heat-conducting zone with different heat conduction pathway densities;

[0018] Wherein, the first heat-conducting partition corresponds to an independent light-emitting unit connected by the first type of connecting part in the vertical projection, the second heat-conducting partition corresponds to an independent light-emitting unit connected by the second type of connecting part in the vertical projection, and the heat-conducting path density of the first heat-conducting partition is greater than that of the second heat-conducting partition.

[0019] Furthermore, the angle between the light guide wall and the light emission direction of the package is in the range of 15° to 45°.

[0020] Furthermore, the sidewall of the second optical cavity is perpendicular to the mounting plane of the substrate, forming a reflective wall; and / or,

[0021] The light guide wall of the first optical cavity is a plane or a concave curved surface.

[0022] Furthermore, the number of the plurality of independent light-emitting units is five, and they are arranged in a straight line;

[0023] Among them, the first and fifth light-emitting units are located at both ends, and the second, third and fourth light-emitting units are located in the middle.

[0024] Furthermore, the first light-emitting unit is a warm white LED chip, and the fifth light-emitting unit is a cool white LED chip; the second, third, and fourth light-emitting units are red, green, and blue LED chips, respectively. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the multi-channel LED light source module of this utility model;

[0026] Figure 2 This is a top view of the multi-channel LED light source module of this utility model;

[0027] Figure 3 This utility model Figure 1 Enlarged structural diagram at point A in the middle.

[0028] Key component symbols: 10, substrate; 11, circuit wiring; 12, first heat-conducting zone; 13, second heat-conducting zone; 20, independent light-emitting unit; 21, first light-emitting unit; 22, second light-emitting unit; 23, third light-emitting unit; 24, fourth light-emitting unit; 25, fifth light-emitting unit; 30, package; 31, first optical cavity; 32, second optical cavity; 33, light guide wall; 40, first type of connection part; 41, second type of connection part. Detailed Implementation

[0029] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0030] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0032] Please see Figure 1 and Figure 2 The image shows a multi-channel LED light source module according to an embodiment of the present invention, comprising:

[0033] The substrate 10 has an insulating and heat-conducting body and circuit wiring 11 disposed thereon;

[0034] Multiple independent light-emitting units 20 are mounted on the same mounting plane of the substrate 10 along an arrangement direction and are electrically connected to the circuit wiring 11 respectively; wherein at least two of the independent light-emitting units 20 are configured to emit light with different center wavelengths;

[0035] The package 30, formed of a light-transmitting material, covers all the independent light-emitting units 20; wherein, a first optical cavity 31 and a second optical cavity 32 with different axial heights are formed within the package 30; the first optical cavity 31 covers at least two of the independent light-emitting units 20 located at both ends of the arrangement direction, and the second optical cavity 32 covers at least one of the independent light-emitting units 20 located in the middle of the arrangement direction; wherein, the axial height of the first optical cavity 31 is less than the axial height of the second optical cavity 32, and at least one inner sidewall of the first optical cavity 31 is a light guide wall 33 inclined toward the second optical cavity 32.

[0036] It is worth noting that the asymmetric optical cavity structure with different axial heights and inclined light guide walls 33 formed within the package 30 enhances light mixing uniformity. Specifically, the first optical cavities 31 located on both sides and their inclined light guide walls 33 actively refract and guide large-angle light emitted from the edge chips to the central region of the module. The deeper second optical cavity 32 located in the middle and its vertical reflective wall provide ample space for cross-mixing of light from the central chip and reflect lateral light back to the mixing area. This synergistic effect allows light of different positions and colors to be efficiently and forcibly mixed within the package 30 (typically within an extremely short distance of less than 2 mm), fundamentally eliminating color spots and color layering phenomena, achieving excellent spatial color uniformity (SCU) on the light-emitting surface, and allowing for exceptionally compact luminaire designs without relying on complex external light mixing structures or long optical paths.

[0037] The number of the plurality of independent light-emitting units 20 is five, and they are arranged in a straight line;

[0038] Among them, the first light-emitting unit 21 and the fifth light-emitting unit 25 are located at both ends, and the second light-emitting unit 22, the third light-emitting unit 23 and the fourth light-emitting unit 24 are located in the middle.

[0039] Furthermore, the first light-emitting unit 21 is a warm white LED chip, and the fifth light-emitting unit 25 is a cool white LED chip;

[0040] The second light-emitting unit 22, the third light-emitting unit 23, and the fourth light-emitting unit 24 are respectively a red LED chip, a green LED chip, and a blue LED chip.

[0041] Please see Figure 3As shown, it further includes a first type of connecting part 40 and a second type of connecting part 41;

[0042] The independent light-emitting units 20 located at both ends of the arrangement direction are electrically connected to the circuit wiring 11 through the first type of connection part 40, and the first type of connection part 40 is a conductive bump.

[0043] The independent light-emitting unit 20 located in the middle of the arrangement direction is electrically connected to the circuit wiring 11 through the second type of connection part 41, which is a bonding wire.

[0044] Specifically, the insulating and heat-conducting body is provided with at least one conductive pad, which constitutes the circuit wiring 11 and is electrically connected and mechanically fixed to the first type of connection part 40.

[0045] The insulating and thermally conductive body forms at least one thermally conductive area in the region outside the conductive pad.

[0046] The heat-conducting area covers multiple independent light-emitting units 20 in the vertical projection and is electrically insulated from the conductive pads.

[0047] In this embodiment, five LED chips, as independent light-emitting units 20, are arranged closely along a straight line in the central region of the upper surface of the ceramic substrate 10. From left to right (see...) Figure 2 (Top view), in order: first light-emitting unit 21 (warm white light), second light-emitting unit 22 (red light), third light-emitting unit 23 (green light), fourth light-emitting unit 24 (blue light), and fifth light-emitting unit 25 (cool white light). The chip size is approximately 30mil × 30mil.

[0048] The first light-emitting unit 21 adopts a flip-chip structure, with a main wavelength covering the broad spectrum of warm white phosphor excited by the blue light chip, and a correlated color temperature (CCT) of 3000K±200K.

[0049] The second light-emitting unit 22 adopts an upright AlInGaP red light chip with a main wavelength of 620nm.

[0050] The third light-emitting unit 23 adopts an upright InGaN green light chip with a main wavelength of 525nm.

[0051] The fourth light-emitting unit 24 adopts an upright InGaN blue light chip with a main wavelength of 450nm.

[0052] The fifth light-emitting unit 25 adopts a flip-chip structure, with a main wavelength covering the broad spectrum of blue light chip excited cool white phosphor, and a correlated color temperature of 6500K±500K.

[0053] The electrical connections employ a hybrid connection method to simultaneously optimize performance and reliability.

[0054] The first type of connection portion 40 (conductive bumps) connects the first light-emitting unit 21 and the fifth light-emitting unit 25 (flip chip) at both ends. The electrodes on the back side of these units are eutectic bonded to the corresponding conductive pads on the substrate 10 via multiple lead-free solder bumps (composition: Sn96.5Ag3.0Cu0.5). This connection simultaneously achieves electrical conduction and mechanical fixation, and has low thermal resistance. After bonding, the height H1 of the chip's light-emitting surface from the surface of the substrate 10 is approximately 50 μm.

[0055] For the second, third, and fourth light-emitting units (upright chips) in the middle section, the second type of connection 41 (bonding wire) is first bonded to the corresponding conductive pads using high thermal conductivity silver paste. Then, double-wire bonding is performed using 1.0 mil diameter gold wire to connect the electrodes on the upper surface of the chip to the other conductive pads on the substrate 10. The bonding wire has a low-curvature arch shape. After this connection is completed, the height H2 of the chip's light-emitting surface from the surface of the substrate 10 is approximately 180 μm. Therefore, before packaging, there is an inherent height difference of approximately ΔH = 130 μm between the middle chip and the chips at both ends.

[0056] The package 30 is integrally molded from existing high-performance packaging materials that meet optical, thermal, and long-term reliability requirements. Those skilled in the art know that existing light-transmitting materials suitable for high-power LED packaging mainly include high-purity epoxy resin, modified silicone resin, and special silicone rubber. Based on the comprehensive requirements of achieving the asymmetric optical cavity structure and long-term reliability of this invention, this embodiment preferably uses addition-reactive silicone gel or silicone rubber, which is widely commercially available in the LED packaging field, as the packaging material. These materials are mature products readily available on the market.

[0057] Specifically, the heat-conducting region includes a first heat-conducting zone 12 and a second heat-conducting zone 13 with different heat conduction pathway densities;

[0058] In this configuration, the first heat-conducting partition 12 corresponds to the independent light-emitting unit 20 connected by the first type of connecting part 40 in the vertical projection, and the second heat-conducting partition 13 corresponds to the independent light-emitting unit 20 connected by the second type of connecting part 41 in the vertical projection. Furthermore, the heat-conducting path density of the first heat-conducting partition 12 is greater than that of the second heat-conducting partition 13.

[0059] In this embodiment, the substrate 10 serves as the mechanical support, electrical interconnection, and heat dissipation core of the module. It employs an advanced thermoelectric separation design to achieve optimal electrical reliability and thermal management performance.

[0060] The main body of the substrate 10 is a square aluminum nitride (AlN) ceramic substrate 10. Its dimensions are, for example, 10.0 mm × 10.0 mm × 0.8 mm. Aluminum nitride ceramic is chosen because it has extremely high thermal conductivity (≥170 W / m·K in this embodiment) and excellent electrical insulation properties. The ceramic substrate 10 is the "insulating and thermally conductive body" in the claims.

[0061] On the upper surface of the ceramic substrate 10, an 11-layer circuit wiring layer is formed using thick film printing, thin film deposition, or DPC (direct copper plating) processes. This layer includes multiple electrically isolated conductive pads and elongated conductive traces (not shown separately in the figure). These conductive pads are used for direct connection to LED chips or as solder joints for gold wire bonding. In this embodiment, there are ten conductive pads in total, divided into five pairs, corresponding to the positive and negative terminals of five LED chips, respectively.

[0062] The ceramic substrate 10 has an interior composed of a complete insulating ceramic material directly below each conductive pad, ensuring electrical isolation. Below the overall area corresponding to the light-emitting unit array, the interior and / or lower surface of the ceramic substrate 10 form a continuous thermally conductive region. This thermally conductive region is physically and electrically completely isolated from the conductive pads on the upper surface, achieving thermoelectric separation where "current flows from the upper conductive pads, and heat is conducted downwards from the substrate 10 body."

[0063] To further optimize heat dissipation, this embodiment employs a refined partitioning design for the heat-conducting region. Below the area corresponding to the two end light-emitting units (first and fifth light-emitting units) in the vertical projection, a first heat-conducting partition 12 is designed. This partition contains a high-density array of thermally conductive vias (e.g., via diameter 80 μm, center-to-center distance 150 μm, filled with pure copper), with a metal fill rate (i.e., thermal conductivity density) greater than 70%. Below the area corresponding to the middle light-emitting units (second, third, and fourth light-emitting units) in the vertical projection, a second heat-conducting partition 13 is designed. This partition contains sparsely distributed thermally conductive vias (e.g., via diameter 100 μm, center-to-center distance 500 μm), with a metal fill rate of approximately 30%. Since flip chips (located at both ends) typically have higher heat flux density, the higher thermal conductivity density of the first heat-conducting partition 12 provides a lower thermal resistance path, achieving differentiated and efficient heat dissipation.

[0064] Preferably, the angle between the light guide wall 33 and the light emission direction of the package 30 is in the range of 15° to 45°. The sidewall of the second optical cavity 32 is perpendicular to the mounting plane of the substrate 10, forming a reflective wall; and / or,

[0065] The light guide wall 33 of the first optical cavity 31 is a plane or a concave curved surface.

[0066] In this embodiment, after chip mounting and connection are completed, the entire substrate 10 is placed in a precision mold. The top of the mold cavity is designed with a specific asymmetrical curved surface, and the bottom supports the substrate 10. Subsequently, high-refractive-index (n≈1.53), high-transmittance, and anti-aging silicone rubber is injected into the mold and cured under vacuum to form an integrally molded package 30. This process completes optical shaping, physical protection, and stress buffering in one step.

[0067] The interior of the package 30 is not a uniform solid, but rather a replica of the mold cavity, forming a functionally differentiated optical cavity structure.

[0068] First optical cavity 31: Covers and encapsulates the first light-emitting unit 21 and the fifth light-emitting unit 25 located at both ends. This cavity is relatively shallow, with its axial height Ha (the distance from the chip's light-emitting surface to the inner surface of the top of the cavity) designed to be approximately 0.6 mm. Most importantly, the inner sidewall of this cavity near the center of the module is constructed as an inclined plane—a light guide wall 33. The angle θ between the light guide wall 33 and the normal to the light emission direction (vertically upward) of the package 30 is designed to be 30° (within a preferred range of 15°-45°).

[0069] To further clarify the preferred angle range of the light guide wall 33, this application systematically studied the light mixing performance under different light guide wall angles θ through optical simulation and experimental verification. The results show that the angle θ between the light guide wall 33 and the normal to the light emission direction is a key parameter affecting the uniformity of spatial color.

[0070] When the included angle θ is set to 15°, the light guide wall 33 is closer to a vertical state. At this angle, its refraction and guiding effect on lateral light is relatively mild, and the light is refracted and directed more towards the far end of the second optical cavity 32. This configuration is suitable for compact designs with small spacing between independent light-emitting units 20 and good light mixing, and can achieve a preliminary improvement in light mixing uniformity with a shallow cavity depth.

[0071] When the included angle θ increases to 45°, the light guide wall 33 tilts significantly, forming a sharper wedge-shaped structure. This configuration can extremely efficiently refract large-angle light emitted from the two light-emitting units downwards and strongly towards the center of the module, forcing it to penetrate deep into the mixing region of the second optical cavity 32. Therefore, in applications where the spacing between the independent light-emitting units 20 is large, or where near-field light mixing requirements are extremely high, the 45° tilt angle can provide the strongest light mixing driving force, effectively suppressing the generation of color spots.

[0072] The aforementioned configurations at 15° and 45°, together with the 30° embodiment described above, constitute a gradient design for light mixing, balanced mixing, and strong mixing requirements. Experimental data show that within this range of 15° to 45°, light of different positions and colors can be efficiently and forcibly mixed within a very short distance inside the package 30, and the spatial color uniformity of the light-emitting surface can meet the requirements of high-end applications.

[0073] Conversely, when the included angle θ is less than 15°, the light guide wall 33 is too steep, its refraction effect is greatly weakened, and it almost degenerates into a regular vertical sidewall, losing its core function of actively guiding edge light to the central area. This results in a sharp decline in the light mixing effect and an inability to effectively eliminate color layering. When the included angle θ is greater than 45°, the light guide wall 33 is excessively tilted. Although the refraction effect is enhanced, it causes a large amount of light to undergo multiple reflections and absorptions in the narrow, sharp corner area between the light guide wall and the light-emitting surface, resulting in significant optical loss and reduced overall light-emitting efficiency. At the same time, an excessively large tilt angle also drastically increases the difficulty of mold forming and the risk of demolding, which is not conducive to mass production.

[0074] Based on the above arguments, this invention preferably defines the angle θ between the light guide wall 33 and the light emission direction as 15° to 45°. This range ensures excellent light mixing uniformity while balancing high light extraction efficiency and good manufacturability, clearly defining its technical limitations and beneficial effects.

[0075] Furthermore, those skilled in the art will understand that the light-transmitting material of the encapsulation 30 can be selected from a variety of existing materials according to actual application requirements, and its refractive index n typically varies in the range of 1.40 to 1.65. To further clarify the influence of the refractive index of the encapsulation material on the design of the light guide wall 33, this utility model provides the following design guidance.

[0076] The light guide wall 33's effect on light refraction and guidance essentially depends on the refraction behavior of light at the inclined interface when it travels from an optically denser medium (encapsulation material, refractive index n) to an optically less dense medium (external air, refractive index ≈ 1). According to Snell's law, at the same incident angle, the higher the refractive index n of the encapsulation material, the stronger the light deflection ability at the interface. Therefore, when encapsulation materials with different refractive indices are used, the optimal tilt angle θ of the light guide wall 33 should be adjusted accordingly to obtain an equivalent light-guiding effect.

[0077] To facilitate independent implementation of this invention by those skilled in the art based on the material's refractive index, an equivalent deflection capability parameter K is defined, satisfying the relationship K = n × sinθ. This parameter K reflects the comprehensive ability of the light guide wall 33 to refract lateral light towards the central region. Optical simulations have verified that when the value of this parameter K falls within the range of approximately 0.35 to 0.60, the forced light mixing effect described in this invention can be effectively achieved.

[0078] Based on the above correlation, when using a packaging material with a higher refractive index n (e.g., n=1.60), the light guide wall angle θ can be appropriately reduced to a lower range of approximately 15° to 30° to achieve the required equivalent deflection capability, while also facilitating a more compact package thickness. Conversely, when using a packaging material with a lower refractive index n (e.g., n=1.40), the light guide wall angle θ needs to be appropriately increased to a higher range of approximately 30° to 45° to compensate for the reduced deflection capability due to the lower refractive index.

[0079] It is understood that the preferred range of the above parameter K corresponds to the range of 15° to 45° between the included angle of the light guide wall. When n takes a value between 1.40 and 1.65 in common packaging materials, those skilled in the art can determine the optimal tilt angle of the light guide wall within the included angle range of 15° to 45° using the above design guidance. This allows the technical solution of this utility model to be universally implemented in a wider range of material selections and to obtain consistently excellent light mixing uniformity.

[0080] Second optical cavity 32: Covers and encloses the second, third, and fourth light-emitting units located in the center. This cavity is relatively deep, with its axial height Hb designed to be approximately 1.2 mm (significantly greater than Ha). The sidewalls of this cavity are substantially perpendicular to the mounting plane of the substrate 10, forming reflective walls. Its top is a smoothly transitioned curved surface.

[0081] It should be noted that the specific values ​​of the axial height Ha of the first optical cavity 31 and the axial height Hb of the second optical cavity 32 are not selected in isolation, but are closely related to the inherent height difference ΔH between the multiple independent light-emitting units 20. This application has found through research that rationally utilizing and compensating for this height difference is one of the keys to achieving the excellent light mixing effect of this invention.

[0082] Specifically, in this embodiment, the independent light-emitting units at both ends (first light-emitting unit 21 and fifth light-emitting unit 25) are connected by conductive bumps, and the height of their light-emitting surfaces from the surface of the substrate 10 is H1 (approximately 50 μm); the independent light-emitting units in the middle (second to fourth light-emitting units) are connected by bonding wires, and the height of their light-emitting surfaces is H2 (approximately 180 μm). Therefore, there is an inherent height difference of ΔH = H2 - H1 ≈ 130 μm between the two types of chips.

[0083] In designing the optical cavity height, this invention actively utilizes this height difference and establishes the following design guiding principles:

[0084] The axial height Ha of the first optical cavity 31 is designed to be greater than or equal to the height H1 of the emitting surface of the independent light-emitting unit it covers, providing an initial light-guiding space. Preferably, Ha satisfies: H1 + 100μm ≤ Ha ≤ H1 + 800μm. This ensures that the package 30 provides sufficient protection for the flip chip while also providing sufficient structural depth for the light guide wall 33 to perform its refractive guiding function.

[0085] The axial height Hb of the second optical cavity 32 is designed to be significantly greater than Ha, and the height difference (Hb - Ha) between it and the first optical cavity 31 is configured to be greater than or equal to the inherent height difference ΔH, i.e., Hb - Ha ≥ ΔH. More preferably, the ratio of Hb to Ha (Hb / Ha) is set in the range of 1.5:1 to 3:1.

[0086] The technical significance of the above design principle lies in the fact that a larger Hb provides ample internal mixing space for the central chip with a higher emitting surface, effectively preventing the emitted light from exiting the emitting surface prematurely without sufficient mixing. Simultaneously, the "stepped" or "tilted" cavity profile formed by the transition from Ha to Hb precisely compensates for the chip's mounting height difference, ensuring that the light emitted by all independent emitting units 20 achieves a relatively balanced longitudinal mixing distance within their respective optical cavities.

[0087] In this embodiment, Ha=0.6mm and Hb=1.2mm are selected, with a ratio of 2:1, which falls within the above-mentioned preferred range. This is the optimal balance point that balances light mixing uniformity and overall thickness of the package 30 under the common height difference configuration of ΔH=130μm, as verified by simulation.

[0088] It is understood that when other connection methods are used, resulting in changes in ΔH, those skilled in the art can adjust the values ​​of Ha and Hb accordingly based on the above design guidelines. For example, when ΔH increases, Hb can be increased (i.e., the Hb / Ha ratio can be increased to close to 3:1) to accommodate a taller central chip; when ΔH decreases, the Hb / Ha ratio can be appropriately reduced (e.g., to close to 1.5:1) to obtain a more compact package thickness.

[0089] Based on the design correlations and patterns revealed above, the optical cavity structure provided by this utility model can achieve excellent light mixing uniformity in different chip height difference application scenarios, and has good process adaptability and feasibility.

[0090] Working principle: The light guide wall 33 of the first optical cavity 31 acts as an optical wedge mirror, refracting large-angle light rays (especially side light) emitted from the flip chips at both ends towards the center of the module, forcing them into the area of ​​the second optical cavity 32. The depth of the second optical cavity 32 and the vertical reflective wall provide ample space for cross-mixing of RGB light, and the reflective wall reflects light attempting to overflow laterally back to the mixing area. Finally, all colors of light are uniformly mixed at a high point inside the package 30 before exiting the device. This achieves "side-guided, center-mixed" light, with an internal mixing distance of less than 1.5mm.

[0091] The upper surface (light-emitting surface) of the package 30 is a smooth micro-arc surface with a large radius of curvature R (e.g., R>50mm), which is approximately flat but can provide a wide-angle Lambertian light output of about 160°.

[0092] In summary, the multi-channel LED light source module in the above embodiments of this utility model has the following beneficial effects;

[0093] The asymmetric optical cavity structure with varying axial heights and inclined light guide walls 33 formed within the package 30 enhances light mixing uniformity. Specifically, the first optical cavities 31 located on both sides and their inclined light guide walls 33 actively refract and guide large-angle light emitted from the edge chips to the central region of the module. The deeper second optical cavity 32 located in the center and its vertical reflective wall provide ample space for cross-mixing of light from the central chip and reflect lateral light back to the mixing area. This synergistic effect allows light of different positions and colors to be efficiently and forcibly mixed within the package 30 (typically within an extremely short distance of less than 2 mm), fundamentally eliminating color spots and color stratification, achieving excellent spatial color uniformity (SCU) on the light-emitting surface, and allowing for exceptionally compact luminaire designs without relying on complex external light mixing structures or long optical paths.

[0094] By employing a hybrid electrical connection system incorporating bonding wires and conductive bumps, and integrating it with the chip layout, the system optimizes electrical connection reliability and adapts to different chip characteristics. Specifically, gold bonding wires connect the centrally mounted chip, which is not sensitive to absolute height, ensuring process maturity and connection flexibility. Solder bumps connect the flip-chips at both ends, which have higher heat dissipation requirements, achieving lower thermal resistance and a more robust mechanical connection. This differentiated connection strategy allows each chip group to operate under its most suitable connection method, improving the overall electrical stability and long-term reliability of the module.

[0095] By employing a thermoelectric separation structure in the substrate 10, particularly the partitioned design with differentiated thermal conductivity density, precise and efficient heat dissipation and a significant reduction in thermal resistance are achieved. Specifically, the physical isolation between the internal thermally conductive areas and the surface conductive pads of the substrate 10 ensures electrical safety and establishes an independent main heat dissipation channel. The first thermally conductive partition 12, with a high thermal conductivity density, covers the flip-chip area, while the second thermally conductive partition 13, with a relatively lower thermal conductivity density, covers the bonded chip area, enabling "on-demand" heat flow management. This design effectively reduces the maximum junction temperature and the temperature difference between chips, thereby significantly improving the stability and lifespan of the module under high-power operation.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. 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 may be combined in any suitable manner in one or more embodiments or examples.

[0097] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A multi-channel LED light source module, characterized in that, include: A substrate having an insulating and thermally conductive body and circuit wiring disposed thereon; Multiple independent light-emitting units are mounted on the same mounting plane of the substrate along an arrangement direction and are electrically connected to the circuit wiring respectively; wherein at least two of the independent light-emitting units are configured to emit light with different center wavelengths; An encapsulation body, formed of a light-transmitting material, covers all the individual light-emitting units; wherein, a first optical cavity and a second optical cavity with different axial heights are formed within the encapsulation body; the first optical cavity covers at least two of the individual light-emitting units located at both ends of the arrangement direction, and the second optical cavity covers at least one of the individual light-emitting units located in the middle of the arrangement direction; wherein, the axial height of the first optical cavity is less than the axial height of the second optical cavity, and at least one inner sidewall of the first optical cavity is a light guide wall inclined toward the second optical cavity.

2. The multi-channel LED light source module according to claim 1, characterized in that, It also includes a first type of connecting part and a second type of connecting part; The independent light-emitting units located at both ends of the arrangement direction are electrically connected to the circuit wiring through the first type of connection part, and the first type of connection part is a conductive bump. The independent light-emitting unit located in the middle of the arrangement direction is electrically connected to the circuit wiring through the second type of connection part, which is a bonding wire.

3. The multi-channel LED light source module according to claim 2, characterized in that, At least one conductive pad is provided on the insulating and heat-conducting body. The conductive pad constitutes the circuit wiring and is electrically connected to the first type of connection part. The insulating and thermally conductive body forms at least one thermally conductive area in the region outside the conductive pad. The heat-conducting area covers multiple independent light-emitting units in the vertical projection and is electrically insulated from the conductive pads.

4. The multi-channel LED light source module according to claim 3, characterized in that, The heat-conducting region includes a first heat-conducting zone and a second heat-conducting zone with different heat-conducting pathway densities. Wherein, the first heat-conducting partition corresponds to an independent light-emitting unit connected by the first type of connecting part in the vertical projection, the second heat-conducting partition corresponds to an independent light-emitting unit connected by the second type of connecting part in the vertical projection, and the heat-conducting path density of the first heat-conducting partition is greater than that of the second heat-conducting partition.

5. The multi-channel LED light source module according to claim 1, characterized in that, The angle between the light guide wall and the light emission direction of the package is in the range of 15° to 45°.

6. The multi-channel LED light source module according to claim 1, characterized in that, The sidewall of the second optical cavity is perpendicular to the mounting plane of the substrate, forming a reflective wall; and / or, The light guide wall of the first optical cavity is a plane or a concave curved surface.

7. The multi-channel LED light source module according to claim 1, characterized in that, The number of the plurality of independent light-emitting units is five, and they are arranged in a straight line; Among them, the first and fifth light-emitting units are located at both ends, and the second, third and fourth light-emitting units are located in the middle.

8. The multi-channel LED light source module according to claim 7, characterized in that, The first light-emitting unit is a warm white LED chip, and the fifth light-emitting unit is a cool white LED chip; the second, third, and fourth light-emitting units are red, green, and blue LED chips, respectively.

Images