Technical solution for facilitating standardization of LED lamp modules

LED lighting is recognized as the next lighting technology due to its power saving, environmental protection and long life, which will replace the existing lighting technology. LED is a cold light source, afraid of heat, 80% of the electrical energy is converted into heat, there must be heat dissipation measures, although LED lighting technology has developed rapidly, there are reports of 200 watts per watt of light, but LED cooling is LED lighting It is a headache, but it has not been solved effectively. It has become a roadblock on the road of universal development of LED lighting.

The biggest problem that hinders the popularization of LED lighting applications is the high price of LED lamps. Although the upstream LED chip manufacturers have divided most of the profits and have a large price reduction space, it is necessary to effectively allocate the entire social resources to the entire industrial chain of LED lighting, effectively reducing Cost, easy for ordinary people to buy and install, LED lighting module standardization is the only way, just like existing lighting (incandescent, fluorescent / energy saving lamps). The obstacle to the standardization of LED lighting modules is the existence of heat dissipation problems.

Heat dissipation is part of heat transfer. Humans have been studying heat transfer for hundreds of years. In the 1960s and 1970s, people were at the peak of heat transfer research. The main driving force was the demand for human aerospace development. At that time, many experts were gathered in the field of heat transfer technology. Many heat transfer researchers became famous people. After that, people's enthusiasm for heat transfer research was gradually reduced. At present, there are very few professionals in heat transfer technology and technology. Heat transfer technology and technology are very mature, just like ripe fruit, falling to the ground and covered by leaves, not being seen by people now, so that when the electronics industry, mainly the CPU in the computer, suddenly increases in heat, People did not pull out the leaves on the ground, pick up the ripe fruit, and transplant the mature heat transfer knowledge into the electronics industry. Instead, it has created a number of new terms: "active cooling", "passive cooling", "heat sinking", etc. It doesn't sound like what it means. English "Sink" is also a very rare term in heat transfer technology and technology.

For the cooling of LED lamps, the current industry lacks clear research results for each heat transfer process in the entire heat transfer process, analyzing: convection (natural) heat transfer from the LED junction to the surface of the air and heat sink, in each process The proportion of heat transfer temperature difference (ie, thermal resistance), which process has the largest temperature difference, that is, the main contradiction, and the factors affecting each heat transfer process, how to reduce the technical direction of its thermal resistance, especially the heat transfer with the largest thermal resistance The process, the technical direction to reduce its thermal resistance is more important. Even with these findings, it must be known to structural engineers because heat transfer is ultimately achieved through structure.

From the perspective of heat transfer technology and technology, LED heat dissipation is not complicated. It only involves a very small part of heat transfer technology - heat conduction heat transfer and convection heat transfer (mainly air natural convection heat transfer), in which heat conduction heat transfer can be utilized. The ready-made heat transfer computer software gets a very accurate solution, such as analyzing the temperature distribution inside the LED package chip (heat transfer process); analyzing the internal temperature distribution from the LED chip to the heat dissipation fin. However, special attention should be paid to the convective heat transfer. When it comes to air flow, it must be studied through a large number of experiments, and computer software calculations have only academic significance and no practical engineering significance. Because the error is too large, there are still many The company is keen to promote such software.

The reasons for the simple problem of LED heat dissipation are: knowledge faults, people with mature heat transfer knowledge are involved in LED heat dissipation research, lack of professional LED heat research institutions, to give clear and correct guiding ideas in the industry, There are so many seminars, but the academic atmosphere is small and the commercial taste is strong. At present, many professional thermal technicians in the industry are transferred from the heat dissipation of computers. Naturally, the commonly used technologies and business activities are brought over. For example, heat pipe technology is widely applied to high-power LED lighting (such as In the streetlights, new business opportunities have been created for heat pipe manufacturers that originally served computer chip coolers. There is even a proposal to use a recirculating heat pipe. If the heat dissipation of the LED lamp uses a general heat pipe like a chicken to kill a pig knife, then the use of a reflux heat pipe is like killing a chicken and lifting the knife. Is there a company in Taiwan that was invented? Liquid immersion cooling technology? The invention of this lack of basic convective heat transfer has also won the Gold Award for the International Invention Exhibition. There are similar enterprises in China, and have a certain popularity, the development of LED liquid cooling technology, said that it has applied for more than 30 patents. These inventors inspired by the car's water tank are not sure why the car's engine uses water (liquid) cooling technology, and the role of water in the heat dissipation process.

This paper proposes a standardization technical solution for implementing LED lighting modules. The heat sink is classified as a component in the luminaire. The wick composed of the LED core and the thermal conductive core will be designed and manufactured into a series of standards, and the cone-shaped thermal core can be effectively solved. The heat conduction between the wick (heat-conducting core) and the heat sink (lamp) enables the wick and the luminaire to be easily disassembled and assembled. The structure is very simple and the cost is low. It is a road to standardization of the module and considers the constant current drive power supply. More reasonable.

Natural convection heat dissipation, no mechanical movement, high reliability, low cost, naturally preferred by LED lights. This paper will explain the principle of natural convection heat dissipation, the maximum heat dissipation and the concept of optimal design. The optimal application structure of the LED lamp heat sink - the sun-type heat sink is proposed. The convection hood is proposed to enhance the heat dissipation by the chimney effect. After a large number of experiments and analysis and research, the results of optimization and strengthening can be achieved, and the level of aluminum for heat dissipation of less than 4 grams per watt can be achieved, and the cost of heat dissipation is significantly reduced. In the future, the cost of heat dissipation will no longer be considered. Not difficult, it will no longer be a problem. (This article does not cover heat transfer within the LED package, which will be addressed and presented in an effective article in a future article.)

Scientific division of modules