Discussion on the myth of LED package cooling

In this report, we will analyze and solve the related questions and myths, including the evaluation of the thermal conductivity and thermal resistance of the package materials, the introduction of the method of measuring the junction temperature, and the suggestion of the package structure.

According to Li Shiwei revealed that this brings the theme of the lecture is cold light thermal management: LED packaging heat dissipation and analysis". He said, LED is a light-emitting cold light source, but since it is a cold light source, then why the heat management?. In this report, we will analyze and solve the related questions and myths, including the evaluation of the thermal conductivity and thermal resistance of the package materials, the introduction of the method of measuring the junction temperature, and the suggestion of the package structure.

Discussion on the myth of LED package cooling

In the interview, Li Shiwei, a reporter for a brief introduction of the thermal effect of high power LED, he said, if the failure of efficient power LED heat dissipation, there will be three kinds of adverse effects:

(1) reduced luminous flux and reduced lumen light efficiency;

(2) light drift;

(3) shortening life.

At the same time, he also mentioned the packaging materials for a wide range of situations such as: from the component level solid crystal, interconnect, bracket, substrate, phosphor, plastic, lens to substrate, module or system level thermal interface, heat sink, all belong to the category of packaging materials, but these are not three words two words can say, if only narrowly plastic material as packaging materials, basically can be divided into two types, namely, epoxy resin (Epoxy) and silica gel (Silicone).

He simply for their differences, the mechanical properties of the former is better, and relatively cheap, but the optical performance is poor, there are long-term use of yellowing problem; the optical properties of the latter is better, high temperature and ultraviolet ability is good, but the poor mechanical properties, and relatively expensive.

In recent years, domestic and foreign packaging companies, many advances have been made in the development and production of high-end packaging products, Li Shiwei think the main progress is reflected in the integration (Integration), such as LED, LED, COB high voltage AC, can be regarded as a form of integration. He believes that the future development trend of packaging technology with the IC process, the future development of LED packaging technology trend to miniaturization and integration (Miniaturization) (Integration), and at the same time to achieve the most ideal solution is both wafer level package (WaferLevelPackaging).

In the international high-tech development change rapidly at the same time, China's packaging industry also faces various challenges, in this regard, he put forward his own opinions and suggestions: "the main domestic LED packaging industry is the problem of homogeneity is too high, we are doing very similar products, only the price competition, vicious competition is the result of the the market mess we are bitter, no company can be established with the scale of the market. The program is through the research and development to cause the difference, from the user experience (User sExperience) and market orientation (MarketDriven) of these two aspects to consider, in order to develop high value-added products (HighAddedValue). "