Analysis of LED lamp cooling structure design

Introduction: there are three main ways of heat conduction, convection and radiation. For bulb, spotlight lamps, conduction mode plays the most important role. In order to obtain good heat conduction effect, the three heat conduction parts should be rationally used as heat conducting material, and the convection heat radiation and heat radiation should be improved as far as possible.

Heat source is very important for heat conduction, heat source comes from two parts: light source and power supply. The heat of the light source, usually pay attention to the effective contact area between the light source PCB and the heat sink, the larger the effective contact area, the better the heat dissipation. In addition, we should pay attention to the heat conduction interface between different media as smooth as possible; the heat conduction between the joints should be close enough, fitting pieces of the contact surface of the gap as small as possible.

In the design of heat conduction, the thermal conduction channel should be to reduce the thermal resistance between the PCB, the heat conducting medium and the heat sink, and increase the effective contact between the three.

Natural convection requires the effective heat transfer area of the same, so under normal circumstances, the heat body roughness can increase the effective heat transfer area; in addition, the different color paint spraying to thermal conductivity and radiation properties of the paint spraying thickness and quality considerations.

In order to increase the heat transfer area of the radiator, we adopt the fin structure. The effective heat transfer area is the 50%-60% of the overall area of the lamp, and the fin type heat sink can determine the effective heat transfer performance according to the fin efficiency and fin spacing.

In natural convection, the power supply will also be hot, because the bulb, the power supply is generally placed in the lamp cavity inside the lamp, can take the use of conductive potting glue or heat conductive mud and other media on the power supply for heat treatment. It is suggested to increase the air layer between the power supply and the LED light source and the PCB fitting platform, so as to form the air partition and weaken the thermal field superposition effect.

In addition, thermal radiation is an energy transfer of all objects at any time. Generally, the radiant intensity of the cool object is lower than that of the warm object. General ball bubble, the radiation heat radiation is small, can be ignored.

In conclusion, the reasonable collocation of LED bulb, lamp products need to consider the heat radiating body and light source, PCB, power supply, selection and design of heat dissipation and heat lamps according to different standards, should not blindly use large radiator or high thermal conductivity materials and cause unnecessary waste of material and cost.