WO2024016823A1

WO2024016823A1 - Light-emitting module and plant lighting lamp

Info

Publication number: WO2024016823A1
Application number: PCT/CN2023/095318
Authority: WO
Inventors: 黄建明; 陈凯
Original assignee: 杭州华普永明光电股份有限公司
Priority date: 2022-07-21
Filing date: 2023-05-19
Publication date: 2024-01-25
Also published as: CN114927513A

Abstract

Disclosed in the present invention are a light-emitting module and a plant lighting lamp using same. The light-emitting module comprises a substrate, a lens board and a light-emitting assembly, the light-emitting assembly being installed on the substrate, the lens board covering the light-emitting assembly, and a lens part being respectively provided at the position on the lens board corresponding to each light-emitting assembly. The light-emitting assembly is a red-light device using a PLCC package, the red-light device comprising a support and at least one red-light chip packaged on the support by means of a protective adhesive, and the side of the protective adhesive facing the lens part is a plane. The part between the lens part and the red-light device using the PLCC package is filled with a filling adhesive, the refractive index of the filling adhesive is within a range plus/minus 0.3 with respect to the refractive index of the protective adhesive. The filling adhesive and the lens part implement joint enhanced extraction of red-light photons emitted by the red-light chip, and meanwhile collectively implement light distribution at a time.

Description

A kind of light-emitting module and plant lighting fixture

Technical field

The present invention relates to the technical field of lighting device design, and in particular to a light-emitting module and a plant lighting fixture.

Background technique

LED plant lighting is a lamp that interferes with plant growth and has a wide market. In plant lighting applications, red LEDs are widely used. Using red light and white light, the spectrum of plant lighting can be effectively adjusted to achieve the purpose of improving PPE.

The red light chips in the light-emitting modules of LED plant lighting currently on the market generally use ceramic packaging, and very few people use the Plastic Leaded Chip Carrier (PLCC) packaging method. The cost of ceramic brackets and auxiliary materials in the ceramic packaging method is higher than that of the brackets and auxiliary materials used in PLCC packaging. Moreover, the production process of the ceramic packaging method is more complex than the PLCC packaging production process and the production efficiency is lower. Therefore, ceramic packaging comprehensive The cost is much higher than that of PLCC packaging.

The ceramic packaging method generally requires a dome (dome) to be installed on the chip. After the red light chip adopts the ceramic packaging method, the light emitted by the chip is less likely to undergo total reflection when it is incident on the surface of the dome. If the same red light chip is packaged in PLCC, although the cost is low, because the front of the PLCC device has protective glue, the surface of the protective glue is a plane, and the light emitted by the photosynthetic photon flux efficiency of the red light chip is incident on the above plane (the surface of the protective glue surface), total reflection is more likely to occur, resulting in

Light extraction efficiency is low. This results in lower Photosynthetic Photon Efficacy (PPE, photosynthetic photon flux efficiency) and lower overall effectiveness in promoting plant growth.

Contents of the invention

In order to solve the aforementioned problems, the present invention provides a light-emitting module, which includes a substrate, a lens plate, and a light-emitting component. The light-emitting component is installed on the substrate, the lens plate is covered on the light-emitting component, and the lens Lenses are provided on the board corresponding to each of the light-emitting components; the light-emitting components include at least one red light device packaged in PLCC, and the red light device includes a bracket and at least one device sealed on the bracket through protective glue. A red light chip, and the side of the protective glue facing the lens part is flat; a filling glue is filled between the lens part and the red light device packaged by PLCC, and the refractive index of the filling glue is at the level of the protective glue. Within the refractive index range of plus or minus 0.3, the filling glue and the lens part realize jointly enhanced extraction of the red light photons emitted from the red light chip, and at the same time, they jointly achieve one-time light distribution.

In some embodiments, the bracket has a recess on a side facing the lens plate, and the red light chip is sealed in the recess through protective glue.

In some embodiments, the inner surface of the recess is provided with a coating for achieving specular reflection and/or diffuse reflection.

In some embodiments, the inner side wall of the recess forms an obtuse angle with the bottom wall of the recess.

In some embodiments, a plurality of red light chips are provided on the bracket, and a barrier is provided between adjacent red light chips.

In some embodiments, the side wall of the barrier portion and the bottom wall of the recess form an obtuse angle.

In some embodiments, the red light chip is surrounded by the sides of the recess and the barrier part, or the red light chip is surrounded by the barrier part.

In some embodiments, when the red light chip is surrounded by the sides of the recess and the barrier, the distance between the sides of the recess and the red light chip is not less than 0.3mm, The distance between the barrier part and the red light chip is not less than 0.3mm; when the red light chip is surrounded by the barrier part, the distance between the barrier part and the red light chip The distance is not less than 0.3mm.

In some embodiments, the height of the barrier is higher than the thickness of the red light chip and lower than the depth of the recess.

In some embodiments, the refractive index of the filling glue is 1.3-1.7.

In some embodiments, the refractive index of the protective glue is the same as the refractive index of the filling glue.

In some embodiments, the wavelength of the red light chip is 655-665nm.

In some embodiments, the protective glue includes a silicone layer placed up and down for protecting the chip and a white glue layer used for increasing reflectivity. The white glue layer is placed close to one side of the substrate, and the red light The chip is at least partially located within the white glue.

In some embodiments, the white glue layer is made of silica gel and silica, or silica gel and titanium dioxide.

In some embodiments, the lens part has a cavity part on the side facing the light-emitting component, the light-emitting component is located in the cavity part, and the space between the cavity part and the light-emitting component is filled with organic matter. The filling glue.

In some embodiments, the lens plate includes at least one lens portion and an extension portion surrounding each lens portion, and the lens portion is arranged opposite to the light-emitting component.

In some embodiments, the light-emitting component further includes at least one white light device.

In some embodiments, the red light chip adopts a vertical packaging structure, the side of the red light chip facing away from the substrate is the negative electrode side, and the side facing the substrate is the positive electrode side, or the red light chip The side facing away from the substrate is the positive electrode side, and the side facing the substrate is the negative electrode side.

In some embodiments, the bracket includes a bracket body and a positive conductive metal part and a negative conductive metal part disposed on the bracket body, between the positive side of each red light chip and the positive conductive metal part , the negative electrode side of each red light chip is electrically connected to the negative electrode conductive metal part, and the red light chip is electrically connected to the substrate through the positive electrode conductive metal part and the negative electrode conductive metal part.

In some embodiments, the side of the red light chip facing away from the substrate is electrically connected to the positive conductive metal part or the negative conductive metal part through wires, and the side of the red light chip facing the substrate The electrical connection with the positive conductive metal part or the negative conductive metal part is directly achieved through the die bonding glue; or the red light chip is directly connected to the positive conductive metal part or the negative conductive metal part by welding on the side facing the substrate. electrical connections between parts.

In some embodiments, the positive conductive metal part and the negative conductive metal part are silver-plated copper sheets.

In some embodiments, the material of the stent body is PCT or EMC.

In some embodiments, the substrate is a PCB board, and the light-emitting component is installed on and connected to the PCB board.

The present invention also proposes a plant lighting fixture, which includes the light-emitting module in the above solution.

Due to the adoption of the above technical solutions, the present invention has the following advantages and positive effects compared with the existing technology:

The light-emitting module provided by the present invention first uses a PLCC-packaged red light device, which has a lower cost than a ceramic package. However, based on the problem that the light extraction efficiency of the PLCC-packaged red light device is relatively low, the present invention combines the lens part and the light-emitting Add filler glue between the components, and use the filler glue to fill the gap between the lens part and the light-emitting component, so that there will be no air left between the lens part and the light-emitting component, and reduce or eliminate total reflection. This is achieved through the filler glue and the lens. The light distribution ensures that the light-emitting module can have high PPE even when using PLCC-encapsulated red light devices.

The dome light source device using ceramic packaging method: its optical path is mainly the light emitted by the chip → dome → air → lens part. There is Fresnel reflection loss at the front and rear interfaces of the air due to the difference in refractive index of different media, and the loss is expected to be about 8%; In this solution, the dome cooperates with the bracket for mounting the chip to complete the primary light distribution of the light source device, while the lens portion completes the secondary light distribution of the light source device. Compared with the solution of the present invention, this solution not only has higher device cost but also has relatively lower PPE.

If the dome light source device using the ceramic packaging method is filled with glue: the main optical path is the red light chip emitting light → dome → filling glue → lens, the optical system optical path is close to the solution of the present invention, but the cost is much higher than the solution of the present invention.

The present invention, through the combination of the PLCC-encapsulated red light device, filler glue, and lens plate, ensures low cost and good PPE at the same time.

Description of drawings

The above and other features and advantages of the present invention can be more clearly understood through the following detailed description in conjunction with the accompanying drawings, in which:

Figure 1 is a schematic structural diagram of a domeless PLCC packaged light source device in the prior art;

Figure 2 is a schematic structural diagram of a domeless PLCC dispensing light source device in the prior art;

Figure 3 is a schematic structural diagram of a dome dispensing light source device in the prior art;

Figure 4 is the current and PPE corresponding curve of a single red light chip with a protective lens;

Figure 5 is a schematic structural diagram of the light-emitting module provided in Embodiment 1 of the present invention;

Figure 6 is a schematic structural diagram of the light-emitting component in Embodiment 1 of the present invention;

Figure 7 is a schematic diagram of the calculation principle of luminous flux in Embodiment 1 of the present invention;

Figure 8 is a schematic diagram of the light emission of the light-emitting component after adding filler glue and lenses in Embodiment 1 of the present invention;

Figure 9 is a top view of the red light chip in Embodiment 2 of the present invention;

Figure 10 is a cross-sectional view of Figure 9;

Figure 11 is a bottom view of the red light chip in Embodiment 2 of the present invention;

Figure 12 is a top view of the red light chip in Embodiment 3 of the present invention;

Figure 13 is a cross-sectional view of Figure 12;

Figure 14 is a bottom view of the red light chip in Embodiment 3 of the present invention;

Figure 15 is a top view of the red light chip in Embodiment 4 of the present invention;

Figure 16 is a bottom view of the red light chip in Embodiment 4 of the present invention;

Figure 17 is a cross-sectional view along line A-A in Figure 16;

Figure 18 is a B-B cross-sectional view in Figure 16;

Figure 19 is a top view of the red light chip in Embodiment 5 of the present invention;

Figure 20 is a bottom view of the red light chip in Embodiment 5 of the present invention;

Figure 21 is a cross-sectional view along line A-A in Figure 20;

Figure 22 is a BB cross-sectional view in Figure 20;

Figure 23 is a top view of the red light chip in Embodiment 6 of the present invention;

Figure 24 is a bottom view of the red light chip in Embodiment 6 of the present invention;

Figure 25 is a cross-sectional view along line A-A in Figure 24;

FIG. 26 is a cross-sectional view along line B-B in FIG. 25 .

Detailed ways

The invention will be described in more detail below with reference to the accompanying drawings showing embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity.

It should be noted in advance that the chips appearing in this article include but are not limited to the red light chips and white light chips appearing below.

First, analyze the following optical system solutions of several existing light source devices assembled in modules with lenses.

As mentioned before, since the manufacturing cost of ceramic packaged light source devices is much higher than that of PLCC packages, in order to reduce manufacturing costs, the industry is committed to improving the light extraction rate under the PLCC package process.

1. Domeless PLCC package light source device:

As shown in Figure 1, this type of light source device includes a PLCC-encapsulated red light chip with a lens set on it. The main optical path is the red light emitted by the chip → plane protective glue → air → lens part; the interface between protective glue → air is due to The loss of total reflection and Fresnel reflection is expected to be more than 18%, and the Fresnel reflection loss at the air → lens interface is about 4%. It can be seen that the light extraction rate of this type of light source device is low. Therefore, it is well known in the art that this type of solution can only be used in scenes that do not require high light extraction rates.

2. Domeless PLCC dispensing light source device:

As shown in Figure 2, this type of light source device includes PLCC-encapsulated chips. Since Scheme 1 has shown that the light extraction rate of the PLCC-encapsulated red light chip is poor after matching with the lens, this type of light source device only uses white light chips, because white light chips are relatively Compared with red light chips, the light extraction rate can be improved. The white light chip is also equipped with a lens, and a filling glue is added between the lens and the chip; the main optical path is the chip emitting white light → protective glue → filling glue → lens part, because the three refractive indexes of the protective glue, filling glue and lens part are relatively close. , its light extraction rate has improved compared to the solution of domeless PLCC packaging white light chip, but the improvement is very limited, only about 8%. Obviously, the addition of filler glue has limited improvement in light extraction rate.

3. Dome dispensing light source device:

As shown in Figure 3, this type of light source device includes a chip, on which a dome and a lens are arranged in sequence, and a filling glue is added between the lens and the dome. The main optical path is the chip emitting light → dome → filling glue → lens. The optical The dome of the system optical path greatly increases the cost, and compared with Scheme 1, the improvement in light extraction rate in Scheme 4 is not obvious enough, only about 8%.

It should be noted here that the dome is a protective glue structure with an upward arc-shaped protrusion at the upper end.

Obviously, even if a dome is added, the filler's improvement in light extraction rate is very limited.

Combining the above solutions, the PLCC red light device without dome and filler glue in Scheme 1 has a light extraction efficiency loss of about 22%. The technical solution of using PLCC encapsulated chip + plane protective glue + filler glue in Scheme 2 is only used for Among white light chips, the white light chip packaged in PLCC has no obvious effect on improving the light extraction rate based on the addition of filler glue. At the same time, because in Scheme 3, the light extraction rate of the combined structure of the light source device of chip + dome + filler + lens is only about 8% higher than that in Scheme 1. It can be seen that, whether it is a white light or red light source, whether there is a dome or not, adding filler glue will have a very limited improvement in the light extraction rate. This makes those skilled in the art believe that adding filler glue will increase the light extraction rate. The effect is not big. Based on this, those skilled in the art would not think of adding filler glue to the domeless structure of a PLCC-encapsulated red light chip in a plant lamp. Because compared to the white light chip of Solution 2, the filler glue has a limited effect on improving the light extraction rate, so for the red light chip that emits worse than the white light chip, the natural light extraction rate will also be worse.

The technicians of the present invention overcame the above technical prejudices and proposed for the first time that the assembly of the red light chip be provided with a flat protective glue and a filling glue at the same time, and there is no dome structure, and the filling glue is used to fill the lens part and the flat protective glue. The gap between the lens part and the light-emitting component prevents air from remaining, reducing or eliminating total reflection, and achieving light distribution through the plane protective glue, filler glue, and lens, thereby greatly improving the light extraction efficiency. At the same time, on the basis of overcoming technical prejudice, the present invention also adopts PLCC packaging, which effectively reduces costs. A light-emitting module with low cost and high light extraction rate is obtained.

The following is a detailed description of specific embodiments:

Example 1

Referring to Figures 5-6, a light-emitting module includes a base plate 1, a lens plate 5, and at least one light-emitting component. The light-emitting component is installed on the base plate 1. The lens plate 5 is covered on the light-emitting component and connected to the base plate 1. The lens plate 5 is provided with a lens portion corresponding to each light-emitting component; the light-emitting component is a red light device packaged by PLCC. The red light device includes a bracket 2 and at least one red light chip 3 packaged on the bracket 2 through a protective glue 4, and The side of the protective glue 4 facing the lens plate 5 is flat. The filler glue 6 is filled between the lens part and the red light device packaged in PLCC. The filler glue 6 and the lens part realize the joint enhanced extraction of the red light photons emitted by the red light chip 3, and at the same time, they jointly achieve disposable Complete lighting.

The light-emitting module provided by the present invention first uses a PLCC-packaged red light device, which has a lower cost than a ceramic package. However, based on the problem that the light extraction efficiency of the PLCC-packaged red light device is relatively low, the present invention combines the lens part and the light-emitting A filler glue 6 is added between the components, and the filler glue 6 is used to fill the gap between the lens part and the light-emitting component. The filler glue 6 and the lens jointly achieve light distribution, ensuring that the light-emitting module uses a PLCC-encapsulated red light device. The situation can also have higher PPE.

What needs to be noted here is that in the absence of filler glue, the light emitted by the red light chip will be significantly deflected and lost at the front and rear interfaces of the air. In the industry, it is generally considered that during the manufacturing process of LED light-emitting devices, changing the process, material and shape of the bracket 2, protective glue 4, and coating can change the light output efficiency and light intensity distribution characteristics, and obtain a preliminary light shape, which is called primary light distribution. . Using lenses or reflectors to further change the light intensity distribution of the light emitted by the LED device to obtain a light spot that meets the lighting requirements is called secondary light distribution. The above-mentioned one-time completion of light distribution means that after the filler 6 is added, the filler 6 couples the device and the lens into a whole, and the light is almost not deflected and lost internally, which is similar to what the industry considers to be a one-time light distribution. , so the light extraction efficiency will be relatively higher.

Among them, a further explanation of the joint enhanced extraction is as follows: a protective glue is placed above the chip. The protective glue process is simple and low-cost. At the same time, a filling glue is provided between the protective glue and the lens part. The refractive index of the filling glue is close to that of the protective glue and the lens part, so that the light emitted by the chip does not or rarely undergoes total reflection at the protective glue → filling glue interface. , and also prevents Fresnel reflection from occurring or rarely occurring at the interface. At the same time, Fresnel reflection does not occur or rarely occurs at the interface between the filler and the lens part. The filling glue not only extracts the total reflected light in Scheme 2, but also extracts the Fresnel reflected light, so that the light emitted by the chip has almost no loss when passing through multiple interfaces of the system. It is an efficient and low-cost method. of joint enhanced extraction.

According to current measured data, adding filler glue between the PLCC device and the lens can increase the light efficiency of the PLCC red light device by about 22%, which is a very obvious improvement.

In this embodiment, the red light chip 3 has a vertical packaging structure. Specifically, the formal structure of the LED chip due to p, The n electrode is on the same side of the LED chip, which is prone to current crowding, and due to the poor thermal conductivity of the sapphire substrate, heat dissipation is seriously hindered. During long-term use, high temperatures caused by poor heat dissipation will affect the performance and transmittance of silica gel, resulting in greater light output power attenuation. Compared with formal LEDs, the vertical packaging structure uses high thermal conductivity substrates (Si, Ge, Cu, etc. substrates) instead of sapphire substrates, which greatly improves heat dissipation efficiency; the two electrodes of the vertical packaging structure LED chip On both sides of the LED epitaxial layer, through the n electrode, almost all the current flows vertically through the LED epitaxial layer, and very little current flows horizontally, which can avoid local high temperatures. In summary, the vertical packaging structure has better heat dissipation, which can improve light efficiency and extend the life of the lamp beads.

In this embodiment, referring to FIG. 6 , the bracket 2 has a recess on the side facing the lens plate 5 , and the red light chip 3 is placed in the recess and encapsulated by the protective glue 4 . In this embodiment, the protective glue 4 can be made of silicone. Of course, in other embodiments, the protective glue 4 can also be made of other materials, which is not limited here.

Furthermore, it is preferable that the side surfaces of the recess are inclined surfaces, and the inclined surfaces extend obliquely outward from the base plate 1 toward the lens plate 5 .

Furthermore, a coating for light reflection is also provided on the inner surface of the recess of the bracket 2 . The coating may specifically be a silver layer or other coating with high reflectivity coated on the surface of the concave part, or a paint coated on the surface of the concave part to achieve diffuse reflection, or a pattern that achieves a mixture of specular or diffuse reflection. The layer is not limited here and can be selected according to specific needs; as a better implementation, in this embodiment, the coating uses a diffuse reflective coating, which can better increase the luminous flux. In this embodiment, through the arrangement of the coating, the light emitted by the red light chip 3 towards the side of the bracket 2 is reflected or totally reflected, and then emitted towards the side of the lens to become effective light, thereby greatly improving the light extraction efficiency.

In this embodiment, one or more light-emitting components are provided on the substrate 1. The number of the light-emitting components can be one or more. There is no limit here, and they can be set according to specific needs. In this embodiment, only one red light chip 3 is packaged on the bracket 2. Of course, multiple red light chips 3 can also be packaged in other embodiments. There is no limitation here and can be adjusted according to specific circumstances.

In addition, in this embodiment, the wavelength of the red light chip 3 is preferably 655-665 nm, and red light in this band is more conducive to plant growth.

In this embodiment, the lens plate 5 includes at least one lens part and an extension part surrounding each lens part. Each lens part is arranged corresponding to each light-emitting component to achieve a light distribution effect. The extension part of the lens plate 5 is used to connect with the base plate 1 , and the connection can be realized through buckles, screws, etc., which is not limited here.

Among them, the lens part has a cavity part on the side facing the light-emitting component, the light-emitting component is located in the cavity part, and the filling glue 6 is filled between the cavity part and the light-emitting component, and preferably, the gap between the cavity part and the light-emitting component is The gaps are filled with the above-mentioned filling glue 6. Preferably in this embodiment, the inner side of the cavity can be arc-shaped, forming an approximately hemispherical cavity, as shown in Figure 5; of course, in other embodiments, the inner side of the cavity can also be flat. , forming an approximately rectangular cavity. There is no restriction here and can be selected according to actual optical design requirements.

In this embodiment, the refractive index of the protective glue 4 is the same as or similar to the refractive index of the filling glue 6 . The refractive index of the filling glue is within the range of plus or minus 0.3 of the refractive index of the protective glue. Specifically, in this solution, the refractive index of the protective glue is 1.528, and the refractive index of the filling glue 6 can be 1.3-1.7. This embodiment helps ensure the light extraction efficiency of the light-emitting module by limiting the refractive index of the filling glue 6 and the protective glue 4 . The refractive index of the filling glue 6 is slightly smaller than the refractive index of the protective glue 4 and is closer to the refractive index of the protective glue 4, which can reduce total reflection, and is slightly higher than the refractive index of the protective glue 4, which can eliminate total reflection. Therefore, total reflection can be reduced as long as the refractive index is higher than that of air. Among them, as the most preferred one, the refractive index of the filling glue 6 and the refractive index of the protective glue 4 are equal. As a suboptimal choice, the refractive index of the filling glue 6 is slightly greater than the refractive index of the protective glue 4 . As the third preferred option, filler glue 6 The refractive index is slightly smaller than the refractive index of the protective glue 4 . Taking all factors into consideration, the preferred refractive index of the filler is 1.3-1.7. The specific refractive index of the filling glue 6 and the protective glue 4 can be selected according to the specific situation and is not limited here.

Among them, the preferred filling glue 6 is silica gel. Of course, other colloids can also be used in other embodiments, as long as the refractive index meets the requirements, the light transmittance is high, and there is no poisonous effect on the lamp beads. There is no limit here.

Further, the substrate 1 is a PCB board, and the light-emitting components are installed on and connected to the PCB board.

The following describes specific embodiments of the luminous flux of the light-emitting module provided by the present invention. The light extraction rate of the light-emitting module can be characterized by the luminous flux value. specific:

The red light chip is an LED chip and is made of material with a refractive index of 2.9. The refractive index of the protective glue is 1.528, the refractive index of the filling glue is 1.42, and the refractive index of the lens is 1.59. Take this as an example.

Set the upper surface of the red light chip as the light-emitting surface, the light intensity distribution as Lambertian distribution, and the peak light intensity as I ₀ .

As shown in Figure 7, S is the light source, the angle φ is the angle between the incident light and the z-axis, 0°≤φ≤90°; the angle θ is the angle between the projection of the incident light in the xoy plane and the x-axis, 0 °≤θ≤360°; I(θ,φ) is the luminous flux φ _source when the angle between the incident light and the z-axis is φ and the angle between the projection of the incident light in the xoy plane and the x-axis is θ. The calculation formula is:

in

Substitute to get:

Based on the above calculation formula of luminous flux φ _source , the luminous flux of the luminous component and the luminous flux of the luminous component after adding filler and lens are calculated respectively:

1. Luminous flux of light-emitting components

As shown in Figure 3-4, when the light emitted from the upper surface of the light-emitting component hits the bonding surface between the protective glue and the air, part of the light is refracted and enters the air, and part of the light is reflected and re-enters the light-emitting component.

Because the refractive index of the protective glue is greater than that of air, total reflection will occur as the incident angle increases. The critical angle is θ _c1 = arcsin (n _air /n _{protective glue} ) = 0.70241. When the incident angle is smaller than θ _c1 , part of the light is refracted and becomes effective light. Another part of the light is reflected and re-enters the protective glue. A lot of this part of the light will be wasted. For simplicity of calculation, the following calculation assumes that this part of the reflected light is wasted.

When the incident angle is from 0° to θ _c1 , integrating the refracted light is the effective light emitted from the light-emitting component:

In the formula, ρ _n is the reflectance of natural light, ρ _s is the reflectance of the component S wave perpendicular to the incident surface, and ρ _p is the reflectance of the component p wave parallel to the incident surface. θ ₁ is the incident angle and θ ₂ is the exit angle. n ₁ is the refractive index of the medium on the incident light side, and n ₂ is the refractive index of the medium on the outgoing light side.
ρ _n =(ρ _s +ρ _p )/2
ρ _s =sin ² (θ ₁ -θ ₂ )/sin ² (θ ₁ +θ ₂ )
ρ _p =tan ² (θ ₁ -θ ₂ )/tan ² (θ ₁ +θ ₂ )
n ₁ ×sinθ ₁ =n2×sinθ ₂

Substituting the above four formulas into formula φ ₁ and substituting into the upper and lower limits of integration, the luminous flux of the light-emitting component can be obtained: φ ₁ =1.21I ₀

(2) The luminous flux of the light-emitting component after adding a lens

When an LED lens is added to the bare board (without filler glue), the calculation of the luminous flux is relatively simple. It is known that the luminous flux of the bare lamp bead is φ _1. When the light emitted by the lamp bead passes through the lens, a reflection loss occurs at the interface between the air and the lens, an absorption loss occurs when passing through the lens, and an absorption loss occurs at the interface between the lens and the air. A reflection loss.

The reflectance formula of two reflections is:
ρ _n =((n-1)/(n+)) ²

Where n is the relative refractive index, n=n ₂ /n ₁ .

When light passes through the interface between air and lens, ρ _n =((1.529-1)/(1.529+1)) ² =4.4%

The material of the LED lens is PC, the absorption rate is 4%/cm, and the absorption ratio is 0.04*0.319=1.3%.

When light passes through the interface between the lens and the air, ρ _n =((0.654-1)/(0.654+1)) ² =4.4%

To sum up, the luminous flux of the ear after the bare board is added with an LED lens (without filler glue) is:
φ ₄ =φ ₁ *95.6%*98.7%*95.6%＝0.9φ ₁

(3) The luminous flux of the light-emitting component after adding filler glue and lens

As shown in Figure 8, when the light emitted from the upper surface of the light-emitting component hits the joint surface of the protective glue and the filling glue, part of the light is refracted and enters the air, and part of the light is reflected and re-enters the light-emitting component. There will also be total reflection at this time. The calculation process is the same as above, except that the critical angle of total reflection θc is different.

Because the refractive index of the protective glue is greater than that of the filling glue, total reflection will occur as the incident angle increases. The critical angle is θ _c2 = arcsin (n _{filling glue} /n _{protective glue} ) = 1.06898. When the incident angle is smaller than θ _c2 , part of the light is refracted and becomes effective light.

Another part of the light is reflected and re-enters the protective glue, and most of this part of the light will be wasted. For simplicity of calculation, the following calculation accelerates this part of the reflected light to be wasted.

When the incident angle is from 0° to θ _c2 , integrating the refracted light is the effective light emitted from the light-emitting component:

The calculation formula is the same as above, and φ ₂ =2.40I is calculated.

At the same time, it is also necessary to consider that after light is refracted into the protective glue, it will continue to hit the joint surface of the protective glue and the lens, and it will continue to hit the joint surface of the lens and air. The light will continue to suffer Fresnel reflection losses on these two surfaces. ;Here it is assumed that light Both are almost perpendicular to the two joining surfaces, and the reflectance ratio of the two reflections is:

ρ ₁ =0.1%, ρ ₂ =5.2%, the two reflection losses total 5.3%;

In the following formula, n is the relative refractive index, n=n ₂ /n ₁
ρ _n =((n-1)/(n+1)) ²

It is also necessary to consider the absorption of light by these materials when the protective glue, filler, and lens pass through. After checking, the absorption rate of silica gel is generally 2.5%/cm. The material of the lens is PC, and the absorption rate is 4%/cm. Further, the thickness of silica gel is about 0.257cm, and the lens is about 0.319cm. Taking this as an example, the total absorption 0.025*0.257+0.04*0.319=1.9%.

The above reflection and absorption losses total 7.2%.

Finally, the luminous flux of the light-emitting component after adding filler glue and lens can be obtained:
φ ₃ =2.4043I ₀ *(1-0.072)＝2.23I ₀

It should be noted that in the calculation process of φ ₃ above, it is assumed that the incidence from the protective glue to the inner curved surface of the lens is almost perpendicular. If it is not vertical incidence at this time, the impact on the transmittance will be very small.

As can be seen from the above, assuming that the reflected or total reflected light is wasted, the luminous flux of a single light-emitting component is 1.21I ₀ at this time, and the luminous flux of the light-emitting component plus filling glue and lens is 2.23I ₀ , filling glue and adding Compared with the single light-emitting component solution, the lens solution can greatly increase the luminous flux, increasing the luminous flux by 84%.

However, in fact, since a coating is provided in the recessed part of the bracket of the light-emitting component, the overall reflectivity of the coating for reflected or totally reflected light is 40%, then:

The total luminous flux of the light-emitting component alone: 1.21I ₀ +(3.1416-1.21)*0.4I ₀ =1.98I ₀

The total luminous flux of the light-emitting component with filler and lens added: 2.23I ₀ +(3.1416-2.40)*0.4*0.928I ₀ =2.51I ₀

At this time, the solution of filling glue and lens can still greatly increase the luminous flux, increasing the luminous flux by 26.8%. Because the power does not change during the calculation process, an increase in luminous flux of 26.8% is equivalent to an increase in light efficiency of 26.8%.

From the above theoretical calculation and analysis process, it can be seen that when there is no filling glue between the protective glue and the lens, the 3.14I ₀ light emitted by the light source only passes through the interface between the protective glue and the air for the first time, with only 1.21I ₀ The light is refracted, which is 38.5%. More than 60% of the light is reflected and fully reflected back into the lamp bead.

After adding filler glue between the protective glue and the lens, when the 3.14I ₀ light emitted by the light source passes through the interface between the protective glue and the air for the first time, 2.4I ₀ light is refracted out, that is, 76.4% of the light transmittance. The pass rate has been greatly improved. This is mainly because the refractive index of the filler glue (1.42) is much larger than that of air, and is close to the refractive index of the protective glue (1.528). This can increase the critical angle of total reflection and greatly reduce total reflection (it can also reduce Fresnel reflection, but mainly reduces total reflection). Even when the refractive index of the filling glue is equal to the protective glue, or when the refractive index of the filling glue is greater than the protective glue, the total reflection will disappear, further increasing the transmittance.

Furthermore, taking the 18PCS, 5050 55mil red light chip as an example, we further illustrate the luminous flux under the same conditions, without adding a lens, adding a lens, adding a lens and filling glue.

Form 1:

18PCS 5050 55mil red light chip, without lens

Form 2:

18PCS 5050 55mil red light chip, including 3160 lens, no filling glue

Form 3:

18PCS 5050 55mil red light chip, including 3160 lens, filled with glue

In the above table, P is the power, Φ is the luminous flux value, PPF is the photosynthetic photon flux, and PPE is the photosynthetic photon flux efficiency.

From the above table, it can be seen without any objection that the values of Φ, PPF and PPE when adding filler + lens are greater than the values when only the lens is added without filler, which shows that the light effect is better.

Example 2

Referring to Figures 9-11, this embodiment is an adjustment based on Embodiment 1.

In this embodiment, the side of the red light chip 3 facing away from the substrate is the negative electrode side, and the side facing the substrate is the positive electrode side; of course, in other embodiments, the side of the red light chip 3 facing away from the substrate can also be the negative electrode side. The positive electrode side, the side facing the substrate, is the negative electrode side.

In this embodiment, the bracket 2 includes a bracket body and a positive conductive metal part 202 and a negative conductive metal part 203 arranged on the bracket body. Between the positive side of the red light chip 3 and the positive conductive metal part 202, the red light chip The negative side of 3 is electrically connected to the negative conductive metal part 203, and the red light chip is electrically connected to the substrate through the positive conductive metal part 202 and the negative conductive metal part 203, thereby realizing the electrical connection between the red light chip and the substrate. .

Furthermore, the red light chip 3 is electrically connected to the negative electrode conductive metal part 203 through the wire 8 on the negative side of the substrate facing away from the substrate, and the red light chip 3 is directly connected to the positive conductive metal part 203 on the positive electrode side of the substrate through the die-bonding glue 7 202 electrical connections. Among them, the components of the die-bonding adhesive 7 are silver powder and epoxy resin, which mainly serve the functions of conducting electricity, dissipating heat, and fixing the chip. Of course, the red light chip 3 facing the anode side of the substrate can also be electrically connected to the anode conductive metal part 202 by direct welding.

Furthermore, in this embodiment, the positive conductive metal part 202 can be split into several parts, specifically a cross-shaped part in the middle opposite to the red light chip 3 and two square parts on one side; red The positive electrode layer at the lower end of the optical chip is electrically connected to the cross-shaped part through the die-bonding glue 7. The cross-shaped part is electrically connected to the two square parts through the wires 9, and the two square parts are electrically connected to the substrate.

In this embodiment, the positive conductive metal part 202 and the negative conductive metal part 203 are made of silver-plated copper sheets, which have the functions of conduction and heat dissipation.

In this embodiment, the bracket body is made of plastic, specifically PCT or EMC plastic, which is not limited here and can be selected according to specific needs.

In this embodiment, as shown in Figure 10, the protective glue 4 includes a silicone layer 401 arranged up and down for protecting the chip and a white glue layer 402 used to increase the reflectivity. The white glue layer 402 is arranged close to the side of the substrate. The red light chip 3 is at least partially located in the white glue 402 . In this embodiment, a white glue layer is added to increase reflectivity and light extraction efficiency.

The material of the white glue layer 402 includes silica gel and silicon dioxide. Of course, the material of the white glue layer 402 can also be silica gel and titanium dioxide.

Other structural forms of the light-emitting module in this embodiment may refer to the description in Embodiment 1, and will not be described again here.

Example 3

This embodiment is an adjustment based on Embodiment 2.

Referring to Figures 12-14, in this embodiment, the positive conductive metal part 202 and the negative conductive metal part 203 are an integral structure, and the negative side on the upper side of the red light chip 3 is electrically connected to the negative conductive metal part 203 through the wire 8 , the lower positive electrode side is electrically connected to the positive electrode conductive metal part 202 through the die bonding glue 7 .

Other structural forms of the light-emitting module in this embodiment may refer to the description in Embodiment 2, and will not be described again here.

Example 4

Referring to Figures 15-18, this embodiment is an adjustment based on Embodiment 2.

In this embodiment, a plurality of red light chips 3 are provided on the bracket, and a barrier 204 is provided between adjacent red light chips.

As mentioned above, the red light chips in the light-emitting modules of LED plant lighting currently on the market generally use ceramic packaging methods, and few people use the Plastic Leaded Chip Carrier (PLCC) packaging method. When multiple small chips are packaged in ceramic packages, the design and production of brackets is relatively difficult and the cost is relatively high. Therefore, ceramic packages are more suitable for packaging a single red light chip. In order to improve PPE, only large-sized and high-brightness chips can be selected, which are relatively expensive.

In the field of plant lighting fixtures, for the packaging of light-emitting devices based on red light chips, although PLCC packaging is cheaper, PPE cannot meet the requirements due to low light extraction efficiency. In order to increase PPE, one can generally think of using multiple red light chips. However, it is frustrating that after using multiple chips, PPE does not increase as expected, but decreases. This has led to technicians giving up the possibility of using PLCC packaging and increasing the number of chips to improve PPE in the field of plant lighting fixtures. As shown in the following table:

Referring to the above test data, it can be seen that, for example, under the condition of 0.89W for dual-core red light particles (i.e., single chip power 0.445W), the PPE is 4.09umol/J, but under the condition of 0.44W for single-core red light particles, the PPE is 4.41 umol/J, the light extraction efficiency is reduced by 7.3%.

However, the inventor found through research that the fundamental reason why the PPE of multiple red light chips decreased was that adjacent red light chips produced mutual extinction effects, thereby affecting the PPE of the plant lighting fixtures.

Although multiple light-emitting chips are also used in the field of general lighting fixtures, they are usually multiple blue-light chips. The blue light emitted by them does not cause the problem of PPE degradation, so technicians cannot detect the differences between adjacent chips. There is a mutual extinction effect. This is because there is phosphor on its light-emitting path. After passing through the phosphor, the blue light turns into yellow light, and the yellow light and blue light mix into white light. The blue light chip absorbs white light and yellow light weakly, which greatly reduces the extinction effect. , so there is no problem of PPE decline.

However, phosphor cannot be used in the light emitting path of a red light chip packaged with PLCC. Therefore, in a scenario where multiple red light chips are used, the PPE of plant lighting fixtures decreases. Those skilled in the art are not aware of the reasons behind this. location.

For the first time, the technicians of the present invention envisioned reducing the current density through two or more low-PPE and low-cost red light chips, and adding barriers between adjacent red light chips 3. part 204, thereby improving the PPE of the entire red light device. Through preliminary experimental verification, the current and PPE corresponding curves of a single red light chip with a protective lens are shown in Figure 4. According to the above experimental data, under the same working environment as the single-chip red light device of a major international manufacturer, the PPE of a single dual-chip red light device has reached 4.38 μmol/J. As the number of chips increases, the PPE will further increase .

In this embodiment, multiple red light chips 3 are provided on one bracket 2 and have the following advantages: (1) The cost is lower when the same chip area is the same, and multiple small chips are much cheaper than large chips of the same area; ( 2) If multiple cores are placed in a light-emitting component, the voltage of this light-emitting component can be more flexible. For example, the voltage of a typical red light chip is about 2V, then the voltage of a single-core red light-emitting component is 2V, while the voltage of a multi-core red light-emitting component can be 2V, or 4V, 6V, 8V, etc.

In this embodiment, two red light chips 3 are disposed in the recess 201 of the bracket 2. Of course, three or more red light chips can also be disposed in other embodiments. It can be adjusted according to specific circumstances and is not restricted here.

As shown in Figure 15; in addition to the upper surface emitting light, the red light chip 3 also emits part of the light from the side. If the red light chips are not separated, the light emitted from the side of the chip will be absorbed by the nearby red light chip, causing extinction. effect. In this embodiment, through the arrangement of the blocking portion 204, it is helpful to prevent the mutual absorption of light between the sides of the chip, thereby helping to improve the light efficiency. The inventor's contribution lies in discovering that the reason is caused by the mutual extinction effect between adjacent red light chips. In other words, this application overcomes the aforementioned technical prejudice and adopts a technical route that technicians abandoned due to technical prejudice, that is, choosing to use the PLCC packaging technology with lower cost and relatively simple technology and increasing the number of chips. By overcoming The mutual extinction effect between multiple red light chips significantly improves PPE.

Moreover, the height of the blocking portion 204 in this embodiment is higher than the height of the red light chip 3, further ensuring the effect of overcoming the extinction phenomenon. At the same time, the height of the barrier part 204 is lower than the depth of the recessed part 201, which ensures that the bracket 2 is flat and has no protrusions after the protective glue 4 is encapsulated, which reduces the uncertainty caused by the subsequent installation of other parts.

In this embodiment, the barrier part 204 is integrally formed with the bracket 2. Compared with other embodiments in which the barrier part 204 is pasted on the bracket 2, in this embodiment, the shape of the bracket 2 can be preset when the mold is opened. Not only the process steps are reduced, but also the cost is reduced. The distance between the side of the recessed portion 201 and the red light chip 3 is not less than 0.3mm, and the distance between the blocking portion 204 and the red light chip 3 The distance between them is not less than 0.3mm, leaving space for the wiring of the red light chip 3. In other embodiments, for example, when five red light chips 2 or nine red light chips 2 are provided, there must be a situation where a certain red light chip 3 is not adjacent to the side of the recess 201 . At this time, the red light chip 3 that is not adjacent to the side of the recessed part 201 is surrounded by the blocking part 204. The distance between the blocking part 204 and the red light chip 3 is not less than 0.3 mm, which is the wiring of the red light chip 3. Space is reserved. This situation can still ensure that the barrier portion 204 is provided between two adjacent red light chips 3 .

In this embodiment, in this embodiment, the side of the red light chip 3 facing away from the substrate is the negative electrode side, and the side facing the substrate is the positive electrode side; of course, in other embodiments, the back side of the red light chip 3 can also be the negative electrode side. The side facing the substrate is the positive electrode side, and the side facing the substrate is the negative electrode side.

In this embodiment, the side of the bracket 2 facing the substrate is provided with a positive conductive metal part 202 and a negative conductive metal part 203. The positive side of each red light chip 3 is electrically connected to the positive conductive metal part 202, and each red light chip 3 is electrically connected to the positive conductive metal part 202. The negative electrode side of the optical chip 3 is electrically connected to the negative electrode conductive metal part 203, and each red light chip is electrically connected to the substrate through the positive electrode conductive metal part 202 and the negative electrode conductive metal part 203, thereby realizing the red light chip and the substrate. At this time, each red light chip 3 is connected in parallel.

Among them, the negative electrode side on the upper side of each red light chip 3 is electrically connected to the negative electrode conductive metal part 203 through the wire 8 , and the positive electrode side on the lower side of each red light chip 3 is electrically connected to the positive electrode conductive metal part 202 through the die bonding glue 7 .

Example 5

Referring to Figures 19-22, this embodiment is an adjustment based on Embodiment 4.

In this embodiment, the positive electrode side of each red light chip is first electrically connected to the metal conductive part 205 through the die bonding glue 7 , and then the metal conductive part 205 is electrically connected to the positive conductive metal part 202 through the wire 9 .

Example 6

Referring to Figures 23-26, this embodiment is an adjustment based on Embodiment 5.

In this embodiment, two red light chips are connected in series.

Specifically, the bracket is provided with a positive conductive metal part 202 and a negative conductive metal part 203, and a metal conductive part 205 is also provided directly below the two red light chips; as shown in Figure 23, the negative side of one of the red light chips passes through The negative electrode conductive metal part 203 of the wire is electrically connected, and the positive electrode side is electrically connected to the metal conductive part 205 below it through the die bonding glue 7. The metal conductive part 205 is then electrically connected to the negative electrode side of another red light chip through the wire, and the other red light chip is electrically connected. The positive side of the chip and the metal conductive part 205 below are electrically connected through the die bonding glue 7. The metal conductive part 205 is electrically connected to the positive conductive metal part 202 through wires, thereby realizing the series connection between the two red light chips, and with electrical connections between substrates.

Example 7

This embodiment provides a plant lighting fixture, which adopts any one of the light-emitting modules in Embodiments 1-6.

Embodiment 8 This embodiment is an adjustment based on Embodiment 1.

The light-emitting component in this embodiment includes multiple red light devices and multiple white light devices.

It will be understood by those skilled in the art that the present invention may be embodied in many other specific forms without departing from its spirit or scope. Although embodiments of the present invention have been described, it should be understood that the present invention should not be limited to these embodiments, and those skilled in the art may make changes and modifications within the spirit and scope of the present invention as defined by the appended claims.

Claims

A light-emitting module, characterized in that it includes a base plate, a lens plate, and a light-emitting component. The light-emitting component is installed on the base board. The lens plate cover is provided on the light-emitting component, and the lens plate is connected to each of the light-emitting components. The corresponding parts of the light-emitting components are respectively provided with lens parts; the light-emitting components include at least one red light device packaged by PLCC, and the red light device includes a bracket and at least one red light chip packaged on the bracket through protective glue. And the side of the protective glue facing the lens part is flat; a filling glue is filled between the lens part and the red light device packaged by PLCC, and the refractive index of the filling glue is plus or minus the refractive index of the protective glue. Within the interval of 0.3, the filling glue and the lens part realize jointly enhanced extraction of the red light photons emitted from the red light chip, and at the same time, they jointly achieve one-time light distribution.
The light-emitting module according to claim 1, wherein the bracket has a concave portion on a side facing the lens plate, and the red light chip is sealed in the concave portion through a protective glue.
The light-emitting module according to claim 2, wherein a coating for achieving specular reflection and/or diffuse reflection is provided on the inner surface of the recess.
The light-emitting module of claim 2, wherein the inner wall of the recess forms an obtuse angle with the bottom surface of the recess.
The light-emitting module of claim 2, wherein a plurality of red light chips are provided on the bracket, and a barrier is provided between adjacent red light chips.
The light-emitting module of claim 5, wherein the side wall of the barrier portion and the bottom surface of the recess form an obtuse angle.
The light-emitting module according to claim 5, characterized in that the red light chip is surrounded by the sides of the recess and the barrier, or the red light chip is surrounded by the barrier. surrounded.
The light-emitting module according to claim 7, characterized in that when the red light chip is surrounded by the sides of the recessed portion and the blocking portion, the sides of the recessed portion and the red light chip The distance between them is not less than 0.3mm, and the distance between the blocking part and the red light chip is not less than 0.3mm; when the red light chip is surrounded by the blocking part, the blocking part The distance from the red light chip is not less than 0.3mm.
The light-emitting module according to claim 5, wherein the height of the blocking portion is higher than the thickness of the red light chip and lower than the depth of the recessed portion.
The light-emitting module according to claim 5, wherein the height of the blocking portion is higher than the thickness of the red light chip and lower than the depth of the recessed portion.
The light-emitting module according to any one of claims 1 to 10, characterized in that the refractive index of the filling glue is 1.3-1.7.
The light-emitting module according to any one of claims 1 to 10, characterized in that the refractive index of the protective glue is the same as the refractive index of the filling glue.
The light-emitting module according to any one of claims 1 to 10, characterized in that the wavelength of the red light chip is 655-665 nm.
The light-emitting module according to any one of claims 1 to 10, characterized in that the protective glue includes a silicone layer arranged up and down for protecting the chip and a white glue layer for increasing reflectivity, and the white glue The layer is arranged close to one side of the substrate, and the red light chip is at least partially located in the white glue.
The light-emitting module according to claim 14, wherein the white glue layer is made of silica gel and silica, or silica gel and titanium dioxide.
The light-emitting module according to any one of claims 1 to 10, characterized in that the lens part faces the light-emitting There is a cavity part on one side of the component, the light-emitting component is located in the cavity part, and the gap between the cavity part and the light-emitting component is filled with the filling glue.
The light-emitting module according to any one of claims 1 to 10, wherein the lens plate includes at least one lens part and an extension part surrounding each lens part, and the lens part is opposite to the light-emitting component. set up.
The light-emitting module according to any one of claims 1 to 10, characterized in that the light-emitting component further includes at least one white light device.
The light-emitting module according to any one of claims 1 to 10, characterized in that the red light chip adopts a vertical packaging structure, the side of the red light chip facing away from the substrate is the negative electrode side, and the side facing the substrate is the negative electrode side. One side of the red light chip is the positive electrode side, or the side of the red light chip facing away from the substrate is the positive electrode side, and the side facing the substrate is the negative electrode side.
The light-emitting module according to claim 19, characterized in that the bracket includes a bracket body and a positive conductive metal part and a negative conductive metal part arranged on the bracket body, and the positive side of each red light chip The negative electrode side of each red light chip is electrically connected to the positive conductive metal part and the negative conductive metal part, and the red light chip is connected to the positive conductive metal part and the negative conductive metal part through The substrate realizes electrical connection.
The light-emitting module according to claim 20, wherein the side of the red light chip facing away from the substrate is electrically connected to the positive conductive metal part or the negative conductive metal part through a wire, and the red light chip is electrically connected to the positive conductive metal part or the negative conductive metal part. The side of the optical chip facing the substrate is directly electrically connected to the positive conductive metal part or the negative conductive metal part through the die bonding glue; or the side of the red light chip facing the substrate is directly connected by welding. Electrical connection with the positive conductive metal part or the negative conductive metal part.
The light-emitting module according to claim 20, wherein the positive conductive metal part and the negative conductive metal part are silver-plated copper sheets.
The light-emitting module according to claim 10, characterized in that the material of the bracket body is PCT or EMC.
The light-emitting module according to any one of claims 1 to 10, characterized in that the substrate is a PCB board, and the light-emitting component is installed on and connected to the PCB board.
A plant lighting fixture, characterized by comprising the light-emitting module according to any one of claims 1-24.