LED packaging device and packaging method

Abstract

The invention relates to an LED packaging device and method, and belongs to the technical field of LED packaging, an electric heat recovery system is arranged to recover heat emitted by an LED assembly and convert the heat into current, the current is used for supplying power to an external battery, heat dissipation of the high-power LED assembly is achieved, meanwhile, the heat is converted into electric quantity and recovered, waste is avoided, and the environment is protected. The control assembly determines whether the power supply end of the LED assembly is the external battery or the power grid according to the electric quantity of the external battery, intelligent regulation and control of the electric quantity stored in the external power supply for power supply of the LED is achieved through two threshold values pre-stored in the control assembly, and heat dissipated by the LED is recycled more effectively. And the plurality of groups of thermoelectric conversion elements are connected in series, so that the heat emitted by the LED can be more effectively recovered.

Description

Technical Field

[0001] The present invention belongs to the technical field of LED packaging, and in particular relates to an LED packaging device and a packaging method. Background Art

[0002] LED, light emitting diode, is a solid-state semiconductor device that can convert electrical energy into visible light. It can directly convert electricity into light. As people's demand for lighting changes, more and more high-power LEDs are produced. The greater the power of the LED, the more energy is lost, and the heat generated will increase accordingly. Under the action of external electrical energy, the radiation recombination of electrons and holes produces electroluminescence. The light radiated near the PN junction needs to pass through the semiconductor medium and packaging structure of the chip itself to reach the outside world. Comprehensive current injection efficiency, radiation luminescence quantum efficiency, chip external light extraction efficiency, etc., in the end, only about 30% to 40% of the input electrical energy is converted into light energy, of which 60% to 70% of the energy is mainly converted into heat energy in the form of lattice vibration caused by non-radiative recombination.

[0003] The LED packaging structure generally packages the LED chip on a packaging substrate, and then seals it with a sealing material to achieve the purpose of waterproofing and moisture-proofing. However, due to the existence of the packaging structure, the heat emitted by the LED chip will be increased and conducted to the external transmission medium, affecting the heat dissipation effect of the LED chip.

[0004] Moreover, even if a heat dissipation device connecting the outside world and the inside of the packaging structure is provided on the packaging structure, on the one hand, if the waterproof and moisture-proof effect of the heat dissipation device is not good, it will directly cause external water vapor to enter the packaging structure and affect the performance of the LED. Therefore, it is difficult to achieve heat dissipation and waterproof and moisture-proof packaging technology in the packaging structure; secondly, even if the heat can be effectively conducted to the outside world, the ratio of heat wasted by high-power LEDs is too large, and coupled with the energy consumption of the heat dissipation device itself, it will further cause waste of electrical energy.

[0005] Therefore, it is necessary to propose a technical solution to recycle the heat wasted by high-power LED lamps. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the present invention provides an LED packaging device and a packaging method to solve the problem of waste caused by heat dissipation of high-power LED lamps.

[0007] The object of the present invention can be achieved by the following technical solution: an LED packaging device, comprising a thermoelectric recovery system encapsulated in a packaging structure, an LED component and an external battery, wherein the thermoelectric recovery system converts the heat conducted by the LED component into an output current to power the external battery;

[0008] The external battery is connected to the power supply circuit of the LED assembly, and the circuit of the external battery and the LED assembly is disconnected in an initial state;

[0009] Also included is a control component, which is electrically connected to an external battery and controls the charging and discharging of the external battery;

[0010] The control component is preset with a charge start threshold and a charge end threshold, and the control component determines whether the power supply end of the LED component is an external battery or a power grid according to the charge start threshold and the charge end threshold:

[0011] When the control component detects that the power level of the external battery is at a charging threshold, the control component controls the external battery to supply power to the LED component;

[0012] When the control component detects that the power level of the external battery reaches a charging end threshold, the control component controls the power grid to supply power to the LED component.

[0013] Preferably, the thermoelectric recovery system comprises a heat-conducting layer, a heat-dissipating layer and a thermoelectric conversion unit, the upper surface of the heat-conducting layer is attached to the bottom of the LED assembly, the heat-conducting layer and the heat-dissipating layer sandwich the thermoelectric conversion unit, and the heat-conducting layer, the heat-dissipating layer and the thermoelectric conversion unit are electrically connected.

[0014] Preferably, the thermoelectric conversion unit includes several groups of thermoelectric conversion elements, one group of thermoelectric conversion elements includes a P-type thermoelectric conversion part and an N-type thermoelectric conversion part that are electrically connected, and the several groups of thermoelectric conversion elements are electrically connected in series.

[0015] Preferably, the LED component comprises a chip and a silicon optical platform, the chip is produced by flip-chip method, a groove is arranged at the center of the silicon optical platform, and a heat absorbing material is arranged on the inner wall of the groove.

[0016] Preferably, the material of the silicon optical platform includes silicon and doped silicon dioxide, silicon-28, silicon-29 and silicon-30.

[0017] Preferably, the P-type thermoelectric conversion part and the N-type thermoelectric conversion part are electrically connected using a conductive medium, and the material of the thermal conductive layer is Cu.

[0018] Preferably, the materials of the P-type thermoelectric conversion part and the N-type thermoelectric conversion part are both Heusler alloys.

[0019] A LED packaging method comprises the following steps:

[0020] S1: flip-chip LED chip on the mounting substrate of LED assembly;

[0021] S2: Install a heat and power recovery system;

[0022] S201: installing a thermoelectric conversion component between the heat-conducting layer and the heat-dissipating layer, wherein the heat-conducting layer is made of copper material;

[0023] S202: connecting the thermoelectric recovery system to an external driving power supply, and connecting the charging end of the external power supply to an output current loop of the thermoelectric recovery system;

[0024] S203: The output end of the external power supply is connected to the power supply circuit of the LED using a magnetic switch circuit;

[0025] S204: installing a control component, electrically connecting the control component to an external power source and realizing control of a switch state of the LED component and a power grid and a switch state of the LED component and an external power source;

[0026] S205: completing electrical testing of the thermal power recovery system circuit;

[0027] In step S2, the circuit connection of the thermal power recovery system is completed on the PCB;

[0028] S3: Connecting the thermal power recovery system and the LED assembly and packaging them;

[0029] S4: Electrical test;

[0030] S5: Install the combination of the thermal power recovery system and the LED component and the packaging structure.

[0031] Preferably, the thermal resistance of the heat conducting layer R th =(L / S)×(1 / f), L is the length of the heat conducting layer, S is the cross-sectional area of ​​the heat conducting layer, and f is the thermal conductivity coefficient of the selected material.

[0032] The beneficial effects of the present invention are as follows: by setting up an electric heat recovery system, the heat emitted by the LED component is recovered and converted into current, and the current is used to power an external battery, so that the heat dissipation of the high-power LED component is achieved while the heat is converted into electricity and recovered, which is both waste-free and environmentally friendly; the control component determines whether the power supply end of the LED component is the external battery or the power grid according to the power of the external battery, and through the two thresholds pre-stored in the control component, the power stored in the external power supply is used for the power supply of the LED itself. Intelligent regulation is achieved, thereby more effectively recovering the heat emitted by the LED; and then the heat emitted by the LED is more effectively recovered by connecting multiple groups of thermoelectric conversion elements in series. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0034] Figure 1 is an external block diagram of the present invention;

[0035] Figure 2 It is a series connection method between several groups of thermoelectric conversion elements of the present invention;

[0036] Figure 3 is a control logic block diagram of the control component of the present invention;

[0037] Main component symbols

[0038] In the figure: 1. LED component; 2. Thermal conductive layer; 3. Heat dissipation layer; 4. Conductive medium. DETAILED DESCRIPTION

[0039] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0040] See also Figure 1-Figure 3 This embodiment provides an LED packaging device, including an LED assembly 1 arranged in a packaging structure, and also including a thermoelectric recovery system packaged in the packaging structure, that is, the LED packaging device of the present application packages all devices or components except the power line or other necessary leads inside the packaging structure, and performs waterproof and moisture-proof treatment on the power line or lead position. In order to reduce the heat generation of the thermoelectric recovery system itself, when using specific components, select components with low energy consumption, and package the heat source of the thermoelectric recovery system close to one end of the outer wall of the packaging structure, so that its heat dissipation is smoother.

[0041] The thermoelectric recovery system includes a heat conductive layer 2, a heat dissipation layer 3 and a thermoelectric conversion unit. The heat conductive layer 2 is configured to conduct the heat generated by the LED component 1. In order not to affect the display range of the LED, the thermoelectric recovery system is installed below the LED component 1, and can also be installed in other places that do not affect the display range of the LED. The thermoelectric recovery system of this embodiment can be a general thermoelectric recovery system that meets the requirements of the present invention regarding the thermoelectric recovery system, that is, it can convert the heat generated by the L high-power LED into electrical energy, that is, convert a large amount of heat generated by the high-power LED into output current. The thermoelectric recovery system is powered by a power grid or an external power supply.

[0042] It also includes an external battery that can be charged and discharged simultaneously. The external battery is encapsulated in the packaging structure. The charging end of the external battery is connected to the output current loop of the thermal power recovery system, and the power supply end of the external battery is connected to the power supply circuit of the LED component 1. Because the heat dissipation temperature around the high-power LED can reach 100°C, but the tolerance temperature of the external battery that can be charged and discharged simultaneously is definitely less than 100°C, when installing it, it is installed below the thermal power recovery system, away from the end of the LED heat source. The external battery that can be charged and discharged simultaneously here can be a general battery that can be charged and discharged simultaneously.

[0043] However, in the initial state, since the LED component 1 is powered by the power grid, the power supply end of the external battery and the circuit of the LED component 1 are disconnected in the initial state. The power grid used to power the LED component 1 can be connected to a conventional 220V voltage in actual production, or it can be connected to other special power supply systems according to the needs of specific LED chips. In order to more intelligently realize the recovery of heat from high-power LEDs, the present invention also includes a control component, which electrically connects the control component and the external battery. A general battery tester that can measure the power storage status of the external battery at any time is provided at the chip position where the control component is located, so that the control component can know the power of the external battery in real time.

[0044] The control component is also configured to control the closing or opening of the LED component 1 and the power grid switch and the closing or opening of the switch of the circuit formed by the external battery and the LED component 1, that is, the switches of the two circuits are set as intelligent switches, and the control component is used to control the two intelligent switches to achieve control of the opening or closing of the two circuits. These intelligent switches can adopt one or other types of control buttons, travel switches, universal conversion switches and master control components. The control component controls the opening or closing state of the two circuits by controlling the opening or closing of the intelligent switches, that is, whether the LED component 1 is powered by the power grid or the external battery, which satisfies the control of the closing or opening of the two circuits by the control component of the present invention.

[0045] The control component sets a charge start threshold Wha and a charge end threshold Whb of the power value of the external battery. The control component determines whether the external battery charges the LED component 1 through the charge start threshold and the charge end threshold:

[0046] When the control component detects that the power level of the external power source is Wha, which is 90% of the full capacity of the external battery, that is, this value indicates that the external battery can be used for external power supply, the control component disconnects the switch connecting the LED component 1 and the power grid, and then the control component controls the external battery to supply power to the LED component 1;

[0047] When the control component detects that the power of the external power supply is WHB, which is 25% of the full load value of the external battery, the control component for protecting the external battery disconnects the external power supply to the LED component 1, and then the control component controls the external battery to supply power to the LED component. However, whether the external battery is used to charge the LED component 1 does not affect the charging of the external battery by the thermal power recovery system.

[0048] This embodiment uses a thermoelectric recovery system to conduct the heat emitted by the high-power LED and recover the heat to generate electricity, thereby meeting the heat dissipation requirements of the LED and recovering the heat, avoiding waste and being green and environmentally friendly.

[0049] In one embodiment, the Seebeck effect is used to connect two different thermoelectric materials (P type and N type) at one end through a good conductor, and the other end is connected to a conductor to form a PN junction, thereby obtaining a simple thermoelectric conversion component, also known as a PN thermoelectric unit. A load resistor is connected to the open end of the thermoelectric unit. At this time, if heat flow (QH) flows into one end of the thermoelectric unit, a high temperature end (i.e., hot end) is formed, and it is lost from the other end (QC) to form a low temperature end (i.e., cold end), so a temperature gradient field is established between the hot end and the cold end of the thermoelectric unit. Driven by the temperature field, the holes and electrons at the high temperature end of the thermoelectric unit begin to diffuse to the low temperature end, thereby forming a potential difference at both ends of the PN electric couple arm, and current will be generated in the circuit. Based on this, the thermoelectric recovery system of this embodiment includes a heat conductive layer 2, a heat dissipation layer 3 and a thermoelectric conversion unit. The upper surface of the heat conductive layer 2 and the lower surface of the LED component 1 are connected using a thermal conductive adhesive. The moisture in the air undergoes a condensation reaction to release low molecules, causing cross-linking and curing, and vulcanization into a high-performance elastomer. The good-adhesive thermal conductive adhesive has excellent resistance to hot and cold alternation, aging resistance and electrical insulation performance, and has excellent moisture resistance, shock resistance, corona resistance, leakage resistance and chemical medium resistance. It can be used continuously at -60 to 280°C and maintain performance. It does not swell and has good adhesion to most metal and non-metal materials; the electrothermal conversion unit is arranged between the thermal conductive layer 2 and the heat dissipation layer 3, that is, the thermal conductive layer 2 and the heat dissipation layer 3 sandwich the electrothermal conversion unit in the middle, and the thermal conductive layer 2 and the heat dissipation layer 3 and the thermoelectric conversion unit are electrically connected. The materials of the thermal conductive layer 2 and the heat dissipation layer 3 can be general thermal conductive materials, but the materials that meet the requirements of the thermal conductive layer 2 and the heat dissipation layer 3 can be the same. The thermoelectric conversion unit is made of PN junction and the thermoelectric conversion unit and the thermal conductive layer 2 and the heat dissipation layer 3 are connected by metal. The metal can be one of copper, aluminum, iron, tungsten, or other materials with good electrical conductivity. In order to adapt to the large amount of heat generated by high-power LEDs, the thermoelectric conversion unit includes multiple groups of thermoelectric conversion elements, one group of thermoelectric conversion elements includes an electrically connected P-type thermoelectric conversion part and an N-type thermoelectric conversion part, and the multiple groups of thermoelectric conversion elements are electrically connected in series through a conductive medium 4. The conductive medium 4 here can be an electrical conductor. The electrical conductor refers to a material with the ability to conduct electric charge, such as copper, iron, aluminum or other media with conductive properties.

[0050] In one embodiment, in order to improve the thermoelectric conversion efficiency of the thermoelectric conversion unit, the P-type thermoelectric conversion part and the N-type thermoelectric conversion part are both made of Heusler alloy.

[0051] In one embodiment, the LED assembly 1 includes a chip and a silicon optical platform. In order to better achieve the heat dissipation effect of the LED, and the current crowding phenomenon is prone to occur in the upright chip, the chip is mounted on the substrate in a flip-chip manner. The flip-chip method of the chip is a technology that connects the chip active area to the substrate with the face down. By directly mounting an external heat sink on the heat sink, the heat in the package is more easily dissipated, thereby reducing the junction temperature and improving the stability of the chip. Compared with the traditional wire bonding process, the flip-chip technology can provide higher I / O density and shorter interconnection length, reduce inductance, resistance and capacitance, and ensure signal delay. The reduction supports higher frequencies, provides better electrical performance, and reduces size: Flip chip technology reduces the height and weight of the chip by using a small IC pin pattern, making the package more compact, etc.; and in order to improve the thermal conductivity of the silicon optical platform, a groove is provided in the center of the silicon optical platform, and the height of the groove is designed to match the display range of the LED, which is adjusted in practice according to the needs of different LEDs, and a heat-absorbing material is provided on the inner wall of the groove to improve the heat dissipation of the LED. The heat-absorbing material can be a general viscous heat-absorbing material, and compounds such as calcium hydroxide and ammonium hydroxide can be selected.

[0052] In order to further improve the heat dissipation of the LED, in one embodiment, the material of the silicon optical platform includes silicon and at least one of silicon dioxide, silicon-28, silicon-29 and silicon-30 doped therein. The addition of silicon dioxide and silicon isotopes can better improve the thermal conductivity of the silicon optical platform.

[0053] This embodiment discloses a method for packaging an LED, comprising the following steps:

[0054] S1: flip-mounting an LED chip on a mounting substrate of an LED assembly 1. The flip-mounting of the chip is to weld the contact points of the chip to the substrate, carrier or circuit board;

[0055] S2: Install a heat and power recovery system;

[0056] S201: Install a thermoelectric conversion component between the heat-conducting layer 2 and the heat-dissipating layer 3. The heat-conducting layer 2 and the heat-dissipating layer 3 are both made of copper material, and the two ends of the thermoelectric conversion component are respectively connected to the heat-conducting layer 2 and the heat-dissipating layer 3 by metal, and the contact surface between the two

[0057] S202: connecting the thermoelectric recovery system to an external driving power supply, and connecting the charging end of the external power supply to an output current loop of the thermoelectric recovery system;

[0058] S203: The output end of the external power supply is connected to the power supply circuit of the LED using a magnetic switch circuit;

[0059] S204: installing a control component, electrically connecting the control component to an external power source and realizing control of a switch state between the LED component 1 and the power grid and a switch state between the LED component 1 and the external power source;

[0060] S205: completing electrical testing of the thermal power recovery system circuit;

[0061] In step S2, the circuit connection of the thermal power recovery system and the installation of the control components are completed by welding on the PCB board, and the PCB board is encapsulated in the LED packaging structure;

[0062] S3: Connecting the thermal power recovery system and the LED assembly 1;

[0063] S301: applying sodium hydroxide on the inner wall of the groove of the silicon platform;

[0064] S302: using thermal conductive adhesive to adhere the lower surface of the LED substrate to the groove of the silicon optical platform, and connect the lower surface of the silicon optical platform and the upper surface of the thermal conductive layer 2 through the thermal conductive adhesive, where the thermal conductive adhesive can be a silicone grease type thermal conductive adhesive;

[0065] S4: packaging other parts of the LED assembly 1, including gluing the chip, selecting the type of phosphor according to specific needs, and installing a lens above the LED assembly 1;

[0066] S5: Testing, including electrical testing of the circuit between the LED assembly 1 and the electrothermal conversion system;

[0067] S6: Use a sealing box with an upper opening to buckle the thermoelectric recovery system cover onto the lower surface of the silicon optical platform. The projected area of ​​the sealing box is smaller than the projected area of ​​the silicon optical platform, and a mounting hole is reserved on the sealing box for installation.

[0068] Following the previous embodiment, this embodiment discloses a flip chip method:

[0069] S101: Wafers for making chips are obtained by using crystal growth technology. Under high temperature and high pressure, NH3 is grown into needle-shaped gallium nitride through liquid Ga, and then fixed into a wafer in a stable form through subsequent methods. Gallium nitride is used to make wafers instead of traditional silicon materials;

[0070] S102: Make LED structure and form metal electrodes. Step 1: Set various photoresist layers on the surface of the wafer, use a mask to expose the layers to ultraviolet light, and then remove the resist by chemical wet etching. Step 2: Form a metal electrode layer composed of Ni-Au on the surface of the P structure by evaporation technology. The metal electrode layer has a certain thickness, and the P area lead is led out through the metal electrode layer film;

[0071] S103: using a wafer dicing machine to cut the wafer into individual LED chips according to a certain size;

[0072] S103: Flip-chip, connecting the chip with bumps to the substrate using a metal bonding method, where fine gold wires are used to bond the metal electrodes of the chip to the substrate;

[0073] S104: bottom filling package, the flip chip and substrate are heated to 70 to 75 degrees, and the filler is injected along the edge of the chip using a syringe filled with filler. Due to the capillary and siphon effect of the gap, the filler is sucked into the gap between the filling chip and the substrate to wrap the bumps. The filler here uses a transparent encapsulation colloid;

[0074] S105: Curing, raising the temperature in stages in an oven until the temperature reaches 130°, and then complete curing is achieved 3-4 hours later.

[0075] S106: Testing the LED chip, including current-voltage characteristic test, luminous flux test, and color parameter test inside the LED component 1.

[0076] Following the above embodiment, this embodiment discloses a method for selecting the optimal size of the heat conducting layer 2:

[0077] Thermal resistance of thermal conductive layer 2 Rth = (L / S) × (1 / f), L is the length of thermal conductive layer 2, S is the cross-sectional area of ​​thermal conductive layer 2, f is the thermal conductivity coefficient of the selected material, thermal conductive layer 2 here uses copper material, f = 264, is the best ratio of length to cross-sectional area of ​​thermal conductive layer 2 tested under test environment, the best thermal resistance value is obtained, and this ratio is used for making thermal conductive layer 2; thermal resistance is a physical quantity that measures the ability of a material or system to hinder the transfer of heat energy, the smaller the thermal resistance, the better the thermal conductivity of the material, for this solution, the same method can be used to obtain the best size or select a relatively better material for the heat dissipation layer 3.

[0078] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An LED packaging device, comprising an LED component arranged in a packaging structure, characterized in that: Also included is a thermoelectric recovery system and an external battery encapsulated in the encapsulation structure, wherein the thermoelectric recovery system converts the heat conducted by the LED assembly into an output current to power the external battery; The external battery is connected to the power supply circuit of the LED assembly, and the circuit of the external battery and the LED assembly is disconnected in an initial state; Also included is a control component, which is electrically connected to an external battery and controls the charging and discharging of the external battery; The control component is preset with a charge start threshold and a charge end threshold, and the control component determines whether the power supply end of the LED component is an external battery or a power grid according to the charge start threshold and the charge end threshold: When the control component detects that the power level of the external battery is at a charging threshold, the control component controls the external battery to supply power to the LED component; When the control component detects that the power level of the external battery reaches a charging end threshold, the control component controls the power grid to supply power to the LED component.

2. The LED packaging device according to claim 1, characterized in that: The thermoelectric recovery system includes a thermal conductive layer, a heat dissipation layer and a thermoelectric conversion unit. The upper surface of the thermal conductive layer is attached to the bottom of the LED component. The thermal conductive layer and the heat dissipation layer sandwich the thermoelectric conversion unit. The thermal conductive layer, the heat dissipation layer and the thermoelectric conversion unit are electrically connected.

3. The LED packaging device according to claim 2, characterized in that: The thermoelectric conversion unit includes a plurality of groups of thermoelectric conversion elements, wherein a group of thermoelectric conversion elements includes a P-type thermoelectric conversion part and an N-type thermoelectric conversion part which are electrically connected, and the plurality of groups of thermoelectric conversion elements are electrically connected in series.

4. The LED packaging device according to claim 1, characterized in that: The LED component comprises a chip and a silicon optical platform. The chip is produced by flip-chip. A groove is arranged in the center of the silicon optical platform. The inner wall of the groove is provided with a heat absorbing material.

5. The LED packaging device according to claim 4, characterized in that: The material of the silicon optical platform includes silicon and doped silicon dioxide, silicon-28, silicon-29 and silicon-30.

6. The LED packaging device according to claim 3, characterized in that: The P-type thermoelectric conversion part and the N-type thermoelectric conversion part are electrically connected by using a conductive medium, and the material of the heat conduction layer is Cu.

7. The LED packaging device according to claim 3, characterized in that: The materials of the P-type thermoelectric conversion part and the N-type thermoelectric conversion part are both Heusler alloy.

8. An LED packaging method, using an LED packaging device according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1: flip-chip LED chip on the mounting substrate of LED assembly; S2: Install a heat and power recovery system; S201: installing a thermoelectric conversion component between the heat-conducting layer and the heat-dissipating layer, wherein the heat-conducting layer is made of copper material; S202: connecting the thermoelectric recovery system to an external driving power supply, and connecting the charging end of the external power supply to an output current loop of the thermoelectric recovery system; S203: The output end of the external power supply is connected to the power supply circuit of the LED using a magnetic switch circuit; S204: installing a control component, electrically connecting the control component to an external power source and realizing control of a switch state of the LED component and a power grid and a switch state of the LED component and an external power source; S205: Complete electrical testing of the thermal power recovery system circuit; In step S2, the circuit connection of the thermal power recovery system is completed on the PCB; S3: Connecting the thermal power recovery system and the LED assembly and packaging them; S4: Electrical test; S5: Install the combination of the thermal power recovery system and the LED component and the packaging structure.

9. The LED packaging method according to claim 8, characterized in that: The thermal resistance R of the thermal conductive layer th =(L / S)×(1 / f), L is the length of the heat conducting layer, S is the cross-sectional area of ​​the heat conducting layer, and f is the thermal conductivity coefficient of the selected material.

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