CN114927513A

CN114927513A - Light-emitting module and plant lighting lamp

Info

Publication number: CN114927513A
Application number: CN202210856381.8A
Authority: CN
Inventors: 黄建明; 陈凯
Original assignee: Hangzhou Hpwinner Opto Corp
Current assignee: Hangzhou Hpwinner Opto Corp
Priority date: 2022-07-21
Filing date: 2022-07-21
Publication date: 2022-08-19
Also published as: WO2024016823A1

Abstract

The invention discloses a light-emitting module and a plant lighting lamp adopting the same, wherein the light-emitting module comprises a substrate, a lens plate and light-emitting components, the light-emitting components are arranged on the substrate, the lens plate covers the light-emitting components, and the positions, corresponding to the light-emitting components, on the lens plate are respectively provided with a lens part; the light-emitting component is a red light device packaged by PLCC, the red light device comprises a support and at least one red light chip packaged on the support by protective glue, and one side of the protective glue facing the lens part is a plane; and filling glue is filled between the lens part and the red light device packaged by PLCC, the refractive index of the filling glue is in the interval of plus or minus 0.3 of the refractive index of the protective glue, and the filling glue and the lens part realize the combined enhanced extraction of red light photons emitted by the red light chip and simultaneously realize the one-time light distribution together.

Description

Light-emitting module and plant lighting lamp

Technical Field

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

Background

The LED plant lighting lamp is a lamp for intervening plant growth and has a wider market. Red LEDs are widely used in plant lighting applications. The red light and the white light are utilized, the spectrum of plant illumination can be effectively adjusted, and the purpose of improving PPE is achieved.

The red light Chip in the light emitting module of the LED plant lighting lamp on the market at present generally adopts a ceramic packaging method, and few people adopt a Plastic LED Chip Carrier (PLCC) packaging method. The cost of the ceramic support and the auxiliary material in the ceramic packaging method is higher than that of the support and the auxiliary material used in PLCC packaging, and the production process of the ceramic packaging method is more complicated than that of the PLCC packaging, and the production efficiency is lower, so the comprehensive cost of the ceramic packaging is far higher than that of the PLCC packaging.

Generally, dome (dome) is required to be arranged on a chip in a ceramic packaging method, and after the red light chip adopts the ceramic packaging method, total reflection is not easy to occur when light emitted by the chip is incident to the surface of the dome. If the same red light chip is packaged by PLCC, although the cost is low, because the front surface of the PLCC device is provided with the 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 easy to be totally reflected when being incident to the plane (the surface of the protective glue), thereby causing the light to be easily reflected

The light extraction efficiency is low. Further, the Photosynthetic Photonic Effect (PPE, i.e., Photosynthetic Photon flux efficiency) is low, and the comprehensive efficiency of promoting plant growth is low.

Disclosure of Invention

In order to solve the foregoing problems, the present invention provides a light emitting module, which includes a substrate, a lens plate, and light emitting elements, wherein the light emitting elements are mounted on the substrate, the lens plate covers the light emitting elements, and lens portions are respectively disposed on the lens plate corresponding to the light emitting elements; the light-emitting component comprises at least one red light device packaged by PLCC, the red light device comprises a support and at least one red light chip packaged on the support by protective glue, and one side of the protective glue facing the lens part is a plane; and filling glue is filled between the lens part and the red light device packaged by PLCC, the refractive index of the filling glue is in the interval of plus or minus 0.3 of the refractive index of the protective glue, and the filling glue and the lens part realize the combined enhanced extraction of red light photons emitted by the red light chip and simultaneously realize the one-time light distribution together.

In some embodiments, the bracket has a recess on a side facing the lens plate, and the red chip is packaged in the recess by a protective adhesive.

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

In some embodiments, the inner side wall of the recess is at an obtuse angle to the bottom wall of the recess.

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

In some embodiments, the side wall of the barrier is at an obtuse angle to the bottom wall of the recess.

In some embodiments, the periphery of the red chip is surrounded by the side of the recess and the barrier, or the periphery of the red chip is surrounded by the barrier.

In some embodiments, when the periphery of the red light chip is surrounded by the side edge of the concave part and the baffle part, the distance between the side edge of the concave part and the red light chip is not less than 0.3mm, and the distance between the baffle part and the red light chip is not less than 0.3 mm; when the periphery of the red light chip is surrounded by the blocking part, the distance between the blocking part and the red light chip is not less than 0.3 mm.

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

In some embodiments, the refractive index of the underfill is in the range of 1.3 to 1.7.

In some embodiments, the refractive index of the protective gel is the same as the refractive index of the filled gel.

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

In some embodiments, the protective glue includes a silica gel layer and a white glue layer, the silica gel layer is arranged up and down and used for protecting the chip, the white glue layer is arranged near one side of the substrate, and the red light chip is at least partially located in the white glue.

In some embodiments, the material of the white glue layer includes silica gel and silicon dioxide, or includes silica gel and titanium dioxide.

In some embodiments, a side of the lens portion facing the light emitting component has a cavity portion, the light emitting component is located in the cavity portion, and the space between the cavity portion and the light emitting component is filled with the filling glue.

In some embodiments, the lens plate includes at least one lens portion and an extension portion surrounding the lens portion, and the lens portion is disposed opposite to the light emitting element.

In some embodiments, the light emitting assembly further comprises at least one white light device.

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

In some embodiments, the bracket includes a bracket body, and a positive conductive metal portion and a negative conductive metal portion disposed on the bracket body, where a positive side of each of the red chips is electrically connected to the positive conductive metal portion, a negative side of each of the red chips is electrically connected to the negative conductive metal portion, and the red chips are electrically connected to the substrate through the positive conductive metal portion and the negative conductive metal portion.

In some embodiments, the side of the red light chip, which faces away from the substrate, is electrically connected with the positive conductive metal part or the negative conductive metal part through a wire, and the side of the red light chip, which faces towards the substrate, is electrically connected with the positive conductive metal part or the negative conductive metal part directly through a die bond; or one side of the red light chip facing the substrate is directly connected with the positive conductive metal part or the negative conductive metal part in a welding mode.

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

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

In some embodiments, the substrate is a PCB board, and the light emitting assembly is mounted on and connected to the PCB board.

The invention also provides a plant lighting lamp which comprises the light-emitting module in the scheme.

Due to the adoption of the technical scheme, compared with the prior art, the invention has the following advantages and positive effects:

according to the light-emitting module provided by the invention, firstly, a PLCC (plastic leaded chip carrier) packaged red light device with lower cost relative to ceramic packaging is selected, but the problem that the light-emitting efficiency of the PLCC packaged red light device is relatively low is solved.

A dome-shaped light source device adopting a ceramic packaging method comprises the following steps: the light path is mainly chip light → dome → air → lens part, Fresnel reflection loss exists in the front interface and the rear interface of the air due to the difference of the refractive indexes of different media, and the expected loss is about 8%; in the scheme, the dome is matched with the bracket for mounting the chip to finish primary light distribution of the light source device, and the lens part finishes secondary light distribution of the light source device. Compared with the scheme of the invention, the scheme has higher device cost and relatively lower PPE.

If the light source device with the dome adopting the ceramic packaging method is filled with glue: the main light path is the light emitted by the red light chip → the dome → the filling glue → the lens, and the light path of the optical system is close to the scheme of the invention, but the cost is far higher than the scheme of the invention.

The invention ensures low cost and better PPE by the combination of the PLCC-packaged red light device, the filling adhesive and the lens plate.

Drawings

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

FIG. 1 is a schematic diagram of a prior art dome-free PLCC packaged light source device;

FIG. 2 is a schematic structural diagram of a dome-free PLCC dispensing light source device in the prior art;

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

FIG. 4 is a graph of the current versus PPE for a single red chip with a protective lens;

fig. 5 is a schematic structural diagram of a light emitting module provided in embodiment 1 of the present invention;

fig. 6 is a schematic structural view of a light emitting device in embodiment 1 of the present invention;

fig. 7 is a schematic view of the principle of light flux calculation in embodiment 1 of the present invention;

fig. 8 is a schematic diagram of light emission of a light emitting device with a filled adhesive and a lens according to embodiment 1 of the present invention;

FIG. 9 is a top view of a red chip in embodiment 2 of the present invention;

FIG. 10 is a cross-sectional view of FIG. 9;

FIG. 11 is a bottom view of a red chip in embodiment 2 of the present invention;

FIG. 12 is a top view of a red light chip in embodiment 3 of the present invention;

FIG. 13 is a cross-sectional view of FIG. 12;

FIG. 14 is a bottom view of a red chip in embodiment 3 of the present invention;

FIG. 15 is a top view of a red chip in embodiment 4 of the present invention;

FIG. 16 is a bottom view of a red chip in embodiment 4 of the present invention;

FIG. 17 is a sectional view taken along line A-A of FIG. 16;

FIG. 18 is a cross-sectional view B-B of FIG. 16;

FIG. 19 is a top view of a red chip in example 5 of the present invention;

FIG. 20 is a bottom view of a red chip in example 5 of the present invention;

FIG. 21 is a sectional view taken along line A-A of FIG. 20;

FIG. 22 is a cross-sectional view B-B of FIG. 20;

FIG. 23 is a top view of a red chip in example 6 of the present invention;

FIG. 24 is a bottom view of a red chip in embodiment 6 of the present invention;

FIG. 25 is a sectional view A-A of FIG. 24;

fig. 26 is a sectional view taken along line B-B in fig. 25.

Detailed Description

The present invention will be described in more detail below with reference to the accompanying drawings, which illustrate 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 that the chips presented herein include, but are not limited to, the red chips and the white chips presented hereinafter.

The following optical system schemes of several existing light source devices assembled in a lens module are first analyzed.

As described above, since the manufacturing cost of the ceramic-packaged light source device is much higher than that of the PLCC package, in order to reduce the manufacturing cost, the industry is focused on improving the light extraction rate under the process of the PLCC package.

1. Dome-free PLCC encapsulated light source device:

as shown in fig. 1, the light source device includes a red light chip packaged by PLCC, and a lens is further disposed thereon, and the main light path is that the chip emits red light → planar protective glue → air → lens portion; the expected loss of the protective adhesive → the air interface is more than 18% due to total reflection and Fresnel reflection, and the Fresnel reflection loss of the air → the lens part interface is about 4%, so that the light-emitting rate of the light source device is low. Therefore, as is well known in the art, such schemes can only be used in scenarios where light extraction is not as demanding.

2. Dome-free PLCC dispensing light source device:

as shown in fig. 2, the light source device includes a chip packaged by a PLCC, and since the light-emitting rate difference between a red chip packaged by the PLCC and a lens is already shown in scheme 1, the light source device only uses a white chip, and the light-emitting rate of the white chip can be improved compared with that of the red chip. A lens is arranged on the white light chip, and filling glue is additionally arranged between the lens and the chip; the main light path is the white light emitted by the chip → the protective glue → the filling glue → the lens part, and the light-emitting rate is improved to a certain extent compared with the scheme of packaging the white light chip without the dome PLCC due to the fact that the refractive indexes of the protective glue, the filling glue and the lens part are relatively close, but the improvement is only about 8% in a very limited way. It is clear that the addition of the filling glue has a limited improvement in the light extraction.

3. There is dome point glue light source device:

as shown in fig. 3, the light source device includes a chip, a dome and a lens are sequentially disposed on the chip, a filling adhesive is additionally disposed between the lens and the dome, and a main light path is light emitted from the chip → the dome → the filling adhesive → the lens, so that the cost of the dome of the light path of the optical system is greatly increased, and compared with scheme 1, the improvement of the light-emitting rate in scheme 4 is not significant enough, and is only about 8%.

And as further explained herein, the dome is a protective glue structure with an upward arc-shaped upper end.

It is clear that even with the addition of domes the glue filling has a very limited improvement in light extraction.

By combining the above schemes, there is a light-emitting efficiency loss of about 22% in the PLCC red light device without the dome and the filling adhesive in scheme 1, and the technical scheme of adopting the chip packaged by the PLCC, the plane protection adhesive and the filling adhesive in scheme 2 is only used in the white light chip, and the light-emitting rate improvement effect of the white light chip packaged by the PLCC is not obvious on the basis of increasing the filling adhesive. Meanwhile, in the scheme 3, the light-emitting rate of the combined structure of the chip, the dome, the filling glue and the lens is only about 8% higher than that of the scheme 1. Therefore, whether the light source is a white light source or a red light source or not, whether the light source has a dome or not, the improvement of the light extraction rate by adding the filling adhesive is very limited, and thus, the improvement effect of the light extraction rate by adding the filling adhesive is not great. Based on this, the person skilled in the art would not think of adding the filling glue in the dome-free structure of the red light chip packaged by the PLCC in the plant lamp. Since the filling adhesive has a limited effect of improving the light-emitting efficiency compared to the white chip of scheme 2, the natural light-emitting efficiency is also worse for the red chip which emits light inferior to the white chip.

The technical personnel of the invention just overcome the technical prejudice, and firstly propose that the plane protection glue and the filling glue are arranged in the assembly of the red light chip, and the dome structure is not provided, the filling glue is used for filling the gap between the lens part and the plane protection glue, so that air is not left between the lens part and the light-emitting component, the total reflection is reduced or eliminated, and the light distribution is realized through the plane protection glue, the filling glue and the lens, thereby greatly improving the light-emitting efficiency. Meanwhile, on the basis of overcoming the technical prejudice, the invention also adopts a PLCC packaging mode, thereby effectively reducing the cost. The light-emitting module with low cost and high light-emitting rate is obtained.

The following is a detailed description of specific embodiments:

example 1

Referring to fig. 5-6, a light emitting module includes a substrate 1, a lens plate 5, and at least one light emitting device, wherein the light emitting device is mounted on the substrate 1, the lens plate 5 covers the light emitting device and is connected to the substrate 1, and lens portions are respectively disposed on the lens plate 5 at positions corresponding to the light emitting devices; the light-emitting component is a red light device packaged by adopting PLCC (plastic leaded chip), the red light device comprises a support 2 and at least one red light chip 3 packaged on the support 2 through a protective adhesive 4, and one side of the protective adhesive 4 facing to the lens plate 5 is a plane. And filling glue 6 is filled between the lens part and the red light device packaged by PLCC, the filling glue 6 and the lens part realize the combined enhanced extraction of the red light photons emitted by the red light chip 3, and simultaneously realize the one-time light distribution together.

According to the light emitting module, the PLCC-packaged red light device with lower cost relative to ceramic packaging is selected, but the problem that the light emitting efficiency of the PLCC-packaged red light device is relatively low is solved.

It should be noted here that, in the absence of the underfill, the light emitted by the red chip is significantly deflected and lost at the front and rear interfaces of the air. In the manufacturing process of the LED light-emitting device, the process, the material and the shape of the bracket 2, the protective glue 4 and the coating are changed in the industry, so that the light-emitting efficiency and the light intensity distribution characteristic can be changed, and the primary light shape is obtained, and is called primary light distribution. The light emitted by the LED device is further changed in light intensity distribution by a lens or a reflector, so that light spots meeting the illumination requirement are obtained, and the secondary light distribution is called. The light distribution is completed once, namely, after the filling adhesive 6 is added, the filling adhesive 6 couples the device and the lens into a whole, light hardly deflects and loses inside, and the light distribution is similar to the once light distribution considered in the industry, so that the light emitting efficiency is relatively higher.

Among these, the further explanation about the combined enhanced extraction is as follows: the protective glue is arranged above the chip, so that the protective glue is simple in process and low in cost. Meanwhile, filling glue is arranged between the protective glue and the lens part, the refractive index of the filling glue is close to that of the protective glue and that of the lens part, so that the light emitted by the chip is not or seldom totally reflected at the interface of the protective glue → the filling glue, and the interface is not or seldom subjected to Fresnel reflection. While no or little fresnel reflection occurs at the interface of the filling glue → lens portion. The filling adhesive extracts not only the light totally reflected in the scheme 2, but also the light reflected by the Fresnel, so that the light emitted by the chip is hardly lost when passing through a plurality of interfaces of the system, and the method is efficient and low-cost combined enhanced extraction.

According to the current measured data, the filling adhesive is additionally arranged between the PLCC device and the lens, the light efficiency of the PLCC red light device can be improved by about 22%, and the improvement is very obvious.

In the present embodiment, the red chip 3 is a vertical package structure. Specifically, the current crowding phenomenon easily occurs in the LED chip with the upright structure because the p electrode and the n electrode are arranged on the same side of the LED chip, and the heat dissipation is seriously hindered because the sapphire substrate has poor heat conductivity. In the long-time use process, the performance and transmittance of the silica gel are affected by high temperature caused by poor heat dissipation, so that greater optical output power attenuation is caused. Compared with a normally-installed LED, the vertical packaging structure adopts a substrate with high thermal conductivity (Si, Ge, Cu and other substrates) to replace a sapphire substrate, so that the heat dissipation efficiency is improved to a great extent; two electrodes of the LED chip of the vertical packaging structure are respectively arranged on two sides of the LED epitaxial layer, and the current almost completely vertically flows through the LED epitaxial layer through the n electrode, so that the current transversely flowing is very little, and the local high temperature can be avoided. To sum up, perpendicular packaging structure heat dissipation is more excellent, can improve the light efficiency and improve the lamp pearl life-span.

In the present embodiment, with reference to fig. 6, the holder 2 has a recess on the side facing the lens plate 5, in which the red chip 3 is placed and encapsulated by a protective glue 4. In this embodiment, the protective adhesive 4 may be a silicone adhesive, and in other embodiments, the protective adhesive 4 may also be made of other materials, which is not limited herein.

Further, it is preferable that the side surface of the concave portion is an inclined surface, and the inclined surface extends obliquely outward from the substrate 1 toward the lens plate 5.

Further, a coating for achieving light reflection is provided on the inner surface of the concave portion of the holder 2. The coating may be a silver layer or other coating with a relatively high reflectivity coated on the surface of the concave portion, or a paint coated on the surface of the concave portion to achieve diffuse reflection, or a mixed coating layer achieving mirror surface or diffuse reflection, which is not limited herein and can be selected according to specific needs; as a preferred embodiment, the coating in this embodiment is a diffuse reflection coating, which can better improve the luminous flux. The coating is arranged in the embodiment, so that the light emitted by the red light chip 3 towards one side of the support 2 is reflected or totally reflected and then emitted towards one side of the lens to form effective light, and the light extraction efficiency is greatly improved.

In this embodiment, one or more light emitting elements are disposed on the substrate 1, and the number of the light emitting elements may be one or more, which is not limited herein and can be set according to specific needs. In this embodiment, only one red chip 3 is packaged on the bracket 2, but a plurality of red chips may be packaged in other embodiments, which is not limited herein and may be adjusted according to specific situations.

In addition, the wavelength of the red light chip 3 in this embodiment is preferably 655-665nm, which is more favorable for plant growth.

In this embodiment, the lens plate 5 includes at least one lens portion and an extending portion surrounding the periphery of each lens portion, and each lens portion and each light emitting component are respectively disposed correspondingly to realize a light distribution effect. The extension of the lens plate 5 is used for connecting with the base plate 1, and the connection can be realized by means of a snap, a screw, and the like, and is not limited herein.

The lens portion has a cavity portion on a side facing the light emitting element, the light emitting element is located in the cavity portion, and the filling adhesive 6 is filled between the cavity portion and the light emitting element, and preferably, a gap between the cavity portion and the light emitting element is filled with the filling adhesive 6. Preferably, the inner side surface of the cavity portion may be curved to form an approximately hemispherical cavity portion, as shown in fig. 5; in other embodiments, the inner side surface of the cavity portion may also be a plane, so as to form an approximately rectangular cavity portion, which is not limited herein and may be selected according to the actual optical design requirement.

In this embodiment, the refractive index of the protective glue 4 is the same as or similar to the refractive index of the filled glue 6. The refractive index of the filling adhesive is within the interval of plus or minus 0.3 of the refractive index of the protective adhesive. Specifically, the refractive index of the protective glue in the scheme is 1.528, and the refractive index of the filling glue 6 can be 1.3-1.7. The embodiment is favorable for ensuring the light-emitting efficiency of the light-emitting module through the limitation of the refractive indexes of the filling adhesive 6 and the protective adhesive 4. The refractive index of the filling adhesive 6 is slightly smaller than that of the protective adhesive 4, the total reflection can be reduced as the refractive index is closer to that of the protective adhesive 4, and the total reflection can be eliminated as the refractive index is slightly higher than that of the protective adhesive 4. Therefore, the total reflection can be reduced as long as the refractive index is higher than that of air. Wherein, as a most preferred choice, the refractive index of the filling glue 6 and the refractive index of the protective glue 4 are equal. As a less preferred option, the refractive index of the filling glue 6 is slightly larger than the refractive index of the protective glue 4. As a third preferred option, the index of refraction of the underfill 6 is slightly less than the index of refraction of the protective gel 4. The refractive index of the preferred underfill is, taken together, 1.3 to 1.7. The specific refractive indexes of the filling adhesive 6 and the protective adhesive 4 can be selected according to specific situations, and are not limited herein.

The preferable filling adhesive 6 is silica gel, and other adhesives can be selected in other embodiments as long as the refractive index meets the requirement, the light transmittance is high, and no toxic effect is caused on the lamp beads, and the method is not limited here.

Further, the substrate 1 is a PCB board, and the light emitting component is mounted on the PCB board and connected thereto.

The following description will be made of the light flux of the light emitting module provided by the present invention with reference to specific embodiments, and the light extraction rate of the light emitting module can be represented by the light flux value. Specifically, the method comprises the following steps:

the red chip is an LED chip, and is made of a material with a refractive index of 2.9, the refractive index of the protective adhesive is 1.528, the refractive index of the filling adhesive is 1.42, and the refractive index of the lens is 1.59, for example.

The upper surface of the red light chip is a luminous surface, the light intensity distribution is Lambert-type distribution, and the peak light intensity is I ₀ ，

As shown in FIG. 7, S is the light source, the angle φ is the angle between the incident light and the z-axis, φ is between 0 and 90; the angle theta is an included angle between the projection of the incident light in the xoy plane and the x axis, and theta is more than or equal to 0 degree and less than or equal to 360 degrees; i (theta, phi) is the luminous flux phi when the included angle between the incident ray and the z-axis is phi and the included angle between the projection of the incident ray in the xoy plane and the x-axis is theta _source The calculation formula of (2) is as follows:

wherein

Substitution can obtain:

based on the above luminous flux phi _source Respectively calculating the luminous flux of the light-emitting component and the luminous flux of the light-emitting component after the filling adhesive and the lens are added:

1. luminous flux of light-emitting component

As shown in fig. 3-4, when light emitted from the top surface of the light emitting assembly hits the combined surface of the protective gel and air, a portion of the light is refracted into the air and a portion of the light is reflected back into the light emitting assembly.

Because the refractive index of the protective glue is larger than that of air, the total reflection phenomenon can occur along with the increase of the incident angle, and the critical angle is theta _c1 =arcsin（n _{Air (a)} /n _{Protective adhesive} ) = 0.70241. When the incident angle is less than theta _c1 When the light is emitted, a part of the light is refracted to become effective light. The other part of the light is reflected and re-enters the protective glue, and the part of the light is wasted, and for the sake of calculation simplicity, the following calculation assumes that the part of the reflected light is wasted.

Incident angle of 0 DEG to theta _c1 When the refraction light is integrated, the effective light emitted out of the light-emitting component is:

in the formula, the first step is that,

is the reflectance of the natural light and is,

is the reflectance of the component S wave perpendicular to the plane of incidence,

is the reflectance of the component p-wave parallel to the plane of incidence.

Is the angle of incidence and is,

is the exit angle. n is ₁ Is the refractive index of the medium on the side of the incident light, n ₂ Is the refractive index of the medium on the side of the outgoing light.

Substituting the four formulas into a formula

Substituting the upper integral limit and the lower integral limit to obtain the luminous flux of the light-emitting component:

=1.21I ₀

(2) luminous flux of light-emitting component with lens

When the bare board is added with the LED lens (no filling glue is added), the luminous flux calculation is simpler. The luminous flux of the known lamp bead bare board is

When light rays emitted by the lamp beads pass through the lens, primary reflection loss occurs at the interface of the air and the lens, absorption loss occurs when the light rays pass through the lens, and primary reflection loss occurs at the interface of the lens and the air.

The reflectance formula of the two reflections is:

where n is the relative refractive index, n = n ₂ / n ₁ 。

When light passes through the air and lens interface

The LED lens was made of PC, had an absorption of 4%/cm and an absorption ratio of 0.04 × 0.319= 1.3%.

When light passes through the lens and air interface

In summary, the luminous flux of the ear after adding the LED lens (without filling glue) to the bare board is:

(3) luminous flux of light-emitting component with filling glue and lens

As shown in fig. 8, when light emitted from the upper surface of the light emitting device is incident on the bonding surface of the protective adhesive and the filling adhesive, a part of the light is refracted into the air, and a part of the light is reflected and re-enters the light emitting device. There is total reflection at this time, and the calculation process is the same as above, except that the critical angle θ c of total reflection is different.

Because the refractive index of the protective glue is larger than that of the filling glue, the total reflection phenomenon can occur along with the increase of the incident angle, and the critical angle is theta _c2 =arcsin（n _{Filling adhesive} /n _{Protective adhesive} ) = 1.06898. When the incident angle is less than theta _c2 In this case, a part of the light is refracted to become effective light. Another part of the light is reflected and re-enters the protective glue, and most of the light is wasted. For simplicity of calculation, the following calculation accelerates this portion of the reflected light to waste.

Incident angle of 0 DEG to theta _c2 When the refraction light is integrated, the effective light emitted out of the light-emitting component is:

the calculation formula is the same as the above, and the calculation is carried out

Meanwhile, the light is refracted into the protective adhesive, then is continuously reflected to a joint surface of the protective adhesive and the lens, and is also continuously reflected to a joint surface of the lens and the air, so that Fresnel reflection loss of the light is continuously generated on the two surfaces; assuming that the light is almost perpendicular to the two junction planes, the reflectance of the two reflections is:

ρ ₁ =0.1%，ρ ₂ 5.2%, and 5.3% of two reflection loss;

in the following formula, n is relative refractive index, n = n ₂ / n ₁

It is also necessary to take into account the absorption of light by the protective glue, the filling glue, the lens as they pass through these materials. The absorption of the silica gel is generally 2.5%/cm, the lens material is PC, the absorption is 4%/cm, the gel thickness of the silica gel is about 0.257cm, and the lens thickness is about 0.319cm, for example, the total absorption is 0.025 × 0.257+0.04 × 0.319= 1.9%.

The above reflection and absorption losses amounted to 7.2%.

Finally, the luminous flux of the light-emitting component with the filling glue and the lens added can be obtained:

note that, above

The calculation of (2) assumes almost normal incidence from the protective gel to the inner curve of the lens. If the incident angle is not vertical, the influence on the transmittance is small。

As can be seen from the above, the luminous flux of the single light emitting component is 1.21I under the assumption that the reflected or totally reflected light is wasted ₀ Luminous flux of the light-emitting component, the filling glue and the lens is 2.23I ₀ Compared with the scheme of a single light-emitting component, the scheme of filling the glue and adding the lens can greatly improve the luminous flux by 84 percent.

In practice, however, since the coating is provided in the recess of the support of the light emitting assembly, the total reflectivity of the coating to the reflected or totally reflected light is 40%, then:

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

Total luminous flux when filling glue and lens in the light emitting module: 2.23I ₀ +（3.1416-2.40）*0.4*0.928I ₀ =2.51I ₀

At this time, the scheme of filling the glue plus lens can still greatly improve the luminous flux by 26.8 percent. Because the power is not changed in the calculation process, the luminous flux increased by 26.8 percent is the luminous efficiency increased by 26.8 percent.

From the above theoretical calculation and analysis process, it can be seen that when no glue is filled between the protective glue and the lens, the light source emits 3.14I ₀ Has only 1.21I when the light firstly passes through the interface of the protective adhesive and the air ₀ The light is refracted out, i.e. 38.5%. More than 60% of the light is reflected and totally reflected back into the lamp bead.

3.14I emitted by the light source after filling glue is added between the protective glue and the lens ₀ Has a 2.4I light passing through the protective glue and air interface for the first time ₀ The light is refracted out, i.e., 76.4%, and the transmittance of the light is greatly improved. This is mainly because the index of refraction of the filled gel is much greater than that of air, 1.42, and the index of refraction of the protective gel is close to 1.528. This can increase the critical angle for total reflection, greatly reducing total reflection (and also fresnel reflection, but mainly total reflection). Even when the refractive index of the filling glue is equal to that of the protective glue, or when the refractive index of the filling glue is larger than that of the protective glue, the total reflection disappears, further improvingA transmittance.

Further, taking an 18PCS and 505055 mil red chip as an example, the luminous flux under the same conditions without a lens, with a lens and with a filling glue will be further described.

A first table:

18PCS 505055 mil Red chip without lens

Serial number	P(W)	Φ(lm)	PPF(μmol/s)	PPE(ppf/W)
					1	8.17	276.05	24.135	2.95
2	10.3	340.14	29.948	2.91
					3	12.06	384.8	34.459	2.86
4	13.89	435.34	39.2	2.82
					5	16.3	495.79	45.028	2.76
6	18.23	545.6	49.843	2.73
					7	20.21	595.3	54.42	2.69

Table two:

18PCS 505055 mil red light chip, 3160 lens, no filling adhesive

Serial number	P(W)	Φ(lm)	PPF(μmol/s)	PPE(ppf/W)
					1	8.163	253.966	22.20	2.71
2	10.28	312.9288	27.55	2.68
					3	12.11	354.016	31.70	2.63
4	13.85	400.5128	36.06	2.59
					5	16.24	456.1268	41.43	2.54
6	18.26	501.952	45.86	2.51
					7	20.17	547.676	50.07	2.47

Table three:

18PCS 505055 mil red light chip including 3160 lens and filling adhesive

Serial number	P(W)	Φ(lm)	PPF(μmol/s)	PPE(ppf/W)
					1	8.161	352.5	29.472	3.61
2	10.29	436.04	36.637	3.56
					3	12.06	498.92	42.265	3.5
4	13.89	565.14	48.159	3.47
					5	16.29	644.87	55.347	3.4
6	18.22	711.29	61.267	3.36
					7	20.19	773.84	66.865	3.31

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

It can be seen from the above table that the values of Φ, PPF, and PPE when the lens is filled with the filling adhesive are greater than those when the lens is not filled with the filling adhesive, so that the visible light efficiency is better.

Example 2

Referring to fig. 9 to 11, this embodiment is an adjustment based on embodiment 1.

In the present embodiment, the side of the red light chip 3 facing away from the substrate is the negative side, and the side facing the substrate is the positive side; of course, in other embodiments, the side of the red light chip 3 facing away from the substrate may be a positive side, and the side facing the substrate may be a negative side.

In this embodiment, the bracket 2 includes a bracket body, and a positive conductive metal portion 202 and a negative conductive metal portion 203 disposed on the bracket body, the positive side of the red light chip 3 is electrically connected to the positive conductive metal portion 202, the negative side of the red light chip 3 is electrically connected to the negative conductive metal portion 203, and the red light chip is electrically connected to the substrate through the positive conductive metal portion 202 and the negative conductive metal portion 203, so that the red light chip is electrically connected to the substrate.

Furthermore, the negative side of the red light chip 3, which faces away from the substrate, is electrically connected with the negative conductive metal part 203 through a wire 8, and the positive side of the red light chip 3, which faces towards the substrate, is directly electrically connected with the positive conductive metal part 202 through the die attach adhesive 7. The die attach adhesive 7 comprises silver powder and epoxy resin, and mainly has the functions of conducting electricity, dissipating heat and fixing a chip. Of course, the red chip 3 may be electrically connected to the positive conductive metal portion 202 by soldering directly on the positive side of the substrate.

Further, in this embodiment, the positive conductive metal portion 202 can be split into several portions, specifically, a cross portion located in the middle and opposite to the red chip 3, and two square portions located on one side; the positive electrode layer at the lower end of the red light chip is electrically connected with the cross-shaped part through the die bond 7, the cross-shaped part is electrically connected with the two square parts through the leads 9 respectively, and the two square parts are electrically connected with the substrate.

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

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

In this embodiment, as shown in fig. 10, the protective adhesive 4 includes a silicon adhesive layer 401 for protecting the chip and a white adhesive layer 402 for increasing the reflectivity, the white adhesive layer 402 is disposed near one side of the substrate, and at least a portion of the red chip 3 is located in the white adhesive layer 402. This embodiment is through increasing the white glue film for improve the reflectivity, improve the light-emitting efficiency.

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

The other structural forms of the light emitting module in this embodiment can refer to the description in embodiment 1, and are not described herein again.

Example 3

This example is an adjustment based on example 2.

Referring to fig. 12-14, in the present embodiment, the positive conductive metal part 202 and the negative conductive metal part 203 are both an integral structure, the negative side of the upper side of the red light chip 3 is electrically connected to the negative conductive metal part 203 through the lead 8, and the positive side of the lower side is electrically connected to the positive conductive metal part 202 through the die bond 7.

The other structural forms of the light emitting module in this embodiment can refer to the description in embodiment 2, and are not described herein again.

Example 4

Referring to fig. 15 to 18, this embodiment is an adjustment based on embodiment 2.

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

As described above, the red light Chip in the light emitting module of the LED plant lighting lamp on the market generally adopts a ceramic packaging method, and few people adopt a Plastic LED Chip Carrier (PLCC) packaging method. When a plurality of small chips are packaged by ceramic packaging, the design and production of the bracket are relatively difficult, and the cost is relatively high, so that the ceramic packaging is more suitable for packaging a single red light chip. In order to improve PPE, only large-sized chips with high brightness can be selected, and the cost is relatively high.

In the field of plant lighting lamps, for packaging a light-emitting device based on a red light chip, although PLCC packaging is cheaper, PPE cannot meet the requirement due to low light extraction efficiency. In order to increase the PPE, it is generally conceivable to use a plurality of red chips, but it is frustrating that the PPE is not increased as expected but decreased after the use of a plurality of chips. This has led to the abandonment of the possibility of increasing PPE by increasing the number of chips and adopting PLCC packaging in the field of plant lighting fixtures. As shown in the following table:

single particle power (W)	0.44	0.56	0.67	0.78	0.89	1.00	1.11
								Single core 60mil 5050 quantity PPE (μmol/J)	4.41	4.35	4.28	4.23	4.16	4.12	4.07
Two-core 60mil 5050 quantity product PPE (μmol/J)	4.23	4.19	4.15	4.12	4.09	4.04	4.02

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

However, the inventor researches to find that the PPE of the plant lighting lamp is reduced due to the fact that the adjacent red light chips generate mutual extinction effect, and therefore the PPE of the plant lighting lamp is affected.

Although a plurality of light emitting chips are also used in the field of general lighting fixtures, a plurality of blue light emitting chips generally do not cause the problem of PPE degradation between the emitted blue light, and therefore, a skilled person cannot find that there is a mutual extinction effect between adjacent chips. The fluorescent powder is arranged on the light emitting path, after passing through the fluorescent powder, the blue light is changed into yellow light, the yellow light and the blue light are mixed to be changed into white light, the blue light chip has weak absorption to the white light and the yellow light, the extinction effect is greatly reduced, and the problem of PPE reduction does not exist.

However, the fluorescent powder cannot be used in the light emitting path of the red light chip packaged by the PLCC, so that the PPE of the plant lighting fixture is rather lowered in a scene where a plurality of red light chips are used, and the person skilled in the art is unaware of the reason behind the PPE.

The technicians of the invention imagine for the first time that the current density is reduced by two or more low cost red light chips with low PPE, and a barrier part 204 is added between two adjacent red light chips 3, thus improving the PPE of the whole red light device. Preliminary experiments verify that the corresponding graph of the current and the PPE of the single red chip with the protective lens is shown in FIG. 4. According to the experimental data, under the same working environment with the single-chip red light device in the international factory, the PPE content of the single-chip red light device in the international factory is 4.38 mu mol/J, and the PPE content is further improved along with the increase of the number of the chips.

In this embodiment, the red chips 3 on one support 2 have the following advantages: (1) the cost is lower under the condition of the same chip area, and a plurality of small chips are much cheaper than large chips with the same area; (2) multiple cores are arranged in one light-emitting component, and the voltage of the light-emitting component can be more flexible. For example, the voltage of a typical red light chip is about 2V, the voltage of a red light emitting component of a single core is 2V, and the voltage of a red light emitting component of a multi-core can be 2V, or 4V, 6V, 8V, and the like.

In the present embodiment, two red light chips 3 are disposed in the recess 201 of the bracket 2, but 3 or more than 3 red light chips may be disposed in other embodiments. Can be adjusted according to specific conditions, and is not limited herein.

As shown in fig. 15; besides the upper surface of the red light chip 3 emits light, the side surface of the red light chip also emits partial light, and if the red light chips are not separated, the light emitted by the side surface of the chip can be absorbed by the adjacent red light chips to generate an extinction effect. The arrangement of the blocking part 204 is favorable for preventing the problem that light between the side faces of the chips is mutually absorbed, so that the light efficiency is favorably improved. The present inventors have contributed to the discovery that the cause thereof is due to the effect of mutual extinction between adjacent red chips. That is to say, the present application overcomes the foregoing technical bias, and adopts a technical route abandoned by technicians due to the technical bias, that is, a technical route of using a PLCC packaging technology with lower cost and relatively simple technology and increasing the number of chips is selected, so as to significantly improve PPE by overcoming the mutual extinction effect between a plurality of red light chips.

Moreover, the height of the blocking portion 204 in this embodiment is higher than that of the red light chip 3, so as to further ensure the effect of overcoming the extinction phenomenon. Meanwhile, the height of the blocking part 204 is lower than the depth of the concave part 201, so that the support 2 is a plane and has no protrusion after the protective adhesive 4 is packaged, and the uncertainty caused by the installation of other subsequent parts is reduced.

In this embodiment, the blocking portion 204 and the bracket 2 are integrally formed, and compared with the manner that the blocking portion 204 is adhered to the bracket 2 in other embodiments, the shape of the bracket 2 can be preset in this embodiment when the mold is opened, so that not only are the process steps reduced, but also the cost is reduced. The distance between the side edge of the concave part 201 and the red light chip 3 is not less than 0.3mm, the distance between the baffle part 204 and the red light chip 3 is not less than 0.3mm, and a space is reserved for 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 is a case where one red light chip 3 is not adjacent to the side of the concave portion 201. At this time, the periphery of the red chip 3 not adjacent to the side of the concave portion 201 is surrounded by the barrier portion 204, and the distance between the barrier portion 204 and the red chip 3 is not less than 0.3mm, thereby reserving a space for wiring of the red chip 3. This situation can still ensure that the barrier portion 204 is disposed between two adjacent red light chips 3.

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

In this embodiment, a positive conductive metal portion 202 and a negative conductive metal portion 203 are disposed on one side of the bracket 2 facing the substrate, a positive side of each red light chip 3 is electrically connected to the positive conductive metal portion 202, a negative side of each red light chip 3 is electrically connected to the negative conductive metal portion 203, and each red light chip is electrically connected to the substrate through the positive conductive metal portion 202 and the negative conductive metal portion 203, so that the red light chips are electrically connected to the substrate, and at this time, the red light chips 3 are connected in parallel.

The negative side of the upper side of each red light chip 3 is electrically connected with the negative conductive metal part 203 through a wire 8, and the positive side of the lower side of each red light chip 3 is electrically connected with the positive conductive metal part 202 through a die bond 7.

Example 5

Referring to fig. 19 to 22, this embodiment is an adjustment based on embodiment 4.

In this embodiment, the positive electrode side of each red light chip is electrically connected to the metal conductive portion 205 through the die bond paste 7, and the metal conductive portion 205 is electrically connected to the positive electrode conductive metal portion 202 through the lead 9.

Example 6

Referring to fig. 23 to 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 metal conductive parts 205 are respectively arranged right below the two red chips; as shown in fig. 23, the negative electrode side of one red light chip is electrically connected to the negative electrode conductive metal portion 203 through a wire, the positive electrode side is electrically connected to the metal conductive portion 205 under the positive electrode side through the die bond 7, the metal conductive portion 205 is electrically connected to the negative electrode side of another red light chip through a wire, the positive electrode side of another red light chip is electrically connected to the metal conductive portion 205 under the positive electrode side through the die bond 7, and the metal conductive portion 205 is electrically connected to the positive electrode conductive metal portion 202 through a wire, so as to realize the series connection between the two red light chips and the electrical connection between the two red light chips and the substrate.

Example 7

The embodiment provides a plant lighting lamp, which adopts any one of the light-emitting modules in the embodiments 1 to 6.

Example 8 this example is a modification based on example 1.

The light emitting assembly in this embodiment includes a plurality of red light devices and a plurality of white light devices.

It will be appreciated by those skilled in the art that the invention can be embodied in many other specific forms without departing from the spirit or scope thereof. Although embodiments of the present invention have been described, it is to be understood that the present invention should not be limited to those precise embodiments, and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined by the appended claims.

Claims

1. A light-emitting module is characterized by comprising a substrate, a lens plate and light-emitting components, wherein the light-emitting components are arranged on the substrate, the lens plate covers the light-emitting components, and lens parts are respectively arranged on the lens plate corresponding to the light-emitting components; the light-emitting component comprises at least one red light device packaged by PLCC, the red light device comprises a support and at least one red light chip packaged on the support by protective glue, and one side of the protective glue facing the lens part is a plane; filling glue is filled between the lens part and a red light device packaged by PLCC, the refractive index of the filling glue is in the range of plus or minus 0.3 of the refractive index of the protective glue, the filling glue and the lens part realize the combined enhanced extraction of red light photons emitted by the red light chip, and simultaneously realize the one-time light distribution.

2. The light emitting module of claim 1, wherein the bracket has a recess on a side facing the lens plate, and the red chip is packaged in the recess by a protective adhesive.

3. The lighting module of claim 2, wherein the recess has a coating disposed on an inner surface thereof for specular and/or diffuse reflection.

4. The lighting module of claim 2, wherein the inner sidewall of the recess is at an obtuse angle with respect to the bottom surface of the recess.

5. The light emitting module as claimed in claim 2, wherein a plurality of red light chips are disposed on the support, and a barrier portion is disposed between adjacent red light chips.

6. The lighting module of claim 5, wherein the sidewall of the barrier portion forms an obtuse angle with the bottom surface of the recess.

7. The light emitting module of claim 5, wherein the periphery of the red light chip is surrounded by the side of the concave portion and the barrier portion, or the periphery of the red light chip is surrounded by the barrier portion.

8. The light emitting module according to claim 7, wherein when the periphery of the red light chip is surrounded by the side edge of the concave portion and the barrier portion, the distance between the side edge of the concave portion and the red light chip is not less than 0.3mm, and the distance between the barrier portion and the red light chip is not less than 0.3 mm; when the periphery of the red light chip is surrounded by the blocking part, the distance between the blocking part and the red light chip is not less than 0.3 mm.

9. The lighting module of claim 5, wherein the height of the barrier is higher than the thickness of the red chip and lower than the depth of the recess.

10. The light emitting module of claim 5, wherein the height of the barrier portion is higher than the thickness of the red light chip and lower than the depth of the recess.

11. The illumination module according to one of claims 1 to 10, wherein the index of refraction of the underfill is 1.3-1.7.

12. The illumination module according to one of claims 1 to 10, wherein the refractive index of the protective glue is the same as the refractive index of the filling glue.

13. The light emitting module as set forth in any one of claims 1-10, wherein the wavelength of the red light chip is 655-665 nm.

14. The light-emitting module according to one of claims 1 to 10, wherein the protective glue comprises a silicone layer and a white glue layer, the silicone layer is arranged from top to bottom and used for protecting the chip, the white glue layer is arranged near one side of the substrate, and at least part of the red light chip is located in the white glue.

15. The illumination module as recited in claim 14, wherein the material of the white glue layer comprises silica gel and silicon dioxide, or silica gel and titanium dioxide.

16. The lighting module of any one of claims 1 to 10, wherein a cavity is formed in a side of the lens portion facing the light emitting element, the light emitting element is located in the cavity, and the space between the cavity and the light emitting element is filled with the filling adhesive.

17. The illumination module as claimed in one of claims 1 to 10, wherein the lens plate comprises at least one lens portion and an extension portion surrounding each lens portion, the lens portion being disposed opposite to the illumination element.

18. The lighting module of any one of claims 1 to 10, wherein the lighting assembly further comprises at least one white light device.

19. The light emitting module according to one of claims 1 to 10, wherein the red light chip is in a vertical package structure, and a side of the red light chip facing away from the substrate is a negative side and a side facing the substrate is a positive side, or a side of the red light chip facing away from the substrate is a positive side and a side facing the substrate is a negative side.

20. The light emitting module of claim 19, wherein the frame comprises a frame body and a positive conductive metal portion and a negative conductive metal portion disposed on the frame body, wherein the positive side of each red chip is electrically connected to the positive conductive metal portion, the negative side of each red chip is electrically connected to the negative conductive metal portion, and the red chips are electrically connected to the substrate through the positive conductive metal portion and the negative conductive metal portion.

21. The light emitting module of claim 20, wherein a side of the red light chip facing away from the substrate is electrically connected to the positive conductive metal portion or the negative conductive metal portion through a wire, and a side of the red light chip facing towards the substrate is electrically connected to the positive conductive metal portion or the negative conductive metal portion directly through a die attach adhesive; or one side of the red light chip facing the substrate is directly connected with the positive conductive metal part or the negative conductive metal part in a welding mode.

22. The lighting module of claim 20, wherein the positive conductive metal part and the negative conductive metal part are silver-plated copper sheets.

23. The lighting module of claim 10, wherein the material of the bracket body is PCT or EMC.

24. The lighting module of any one of claims 1 to 10, wherein the substrate is a PCB board, and the light emitting component is mounted on and connected to the PCB board.

25. A plant lighting fixture, comprising the light emitting module of any one of claims 1-24.