Low cost LED packaging technology emerging in recession

At the same time to achieve high output and low cost

The scope of application of LED is extending from the signal display to the broad market including LCD panel backlight and lighting. The key factor for the expansion of applications is the ever decreasing price, while there are many technologies for display applications to provide low-cost LED packaging. In general, this area can be divided into lower component costs, as well as lower cost manufacturing processes.

To extend the life of the plastic

In applications such as LCD panel backlighting and lighting, LED is often used to output more than 1W. The heat generated by the high output power LED not only reduces the luminous efficiency, but also reduces the quality of the packaging material itself. Therefore, the key is to address these issues, as well as reduce packaging costs.

Japan's Matsushita Electric (Panasonic ELectric Works) has developed a plastic substrate and can improve the radiation performance of the radiator (Figure 8). Metal substrates, such as aluminum, provide a higher level of radiation, but at a higher cost. As a result, the company abandoned the metal, trying to improve the thermal radiation properties of plastic substrates to extend the service life. Matsushita Electric has improved the process of adding two layers of copper into the plastic layer, and the thermal conductivity of the substrate increased from 1W/mK to 2W/mK or 3W/mK. The company explained that the heat radiation performance of the plastic substrate than aluminum, but the company will continue to develop, in order to achieve thermal efficiency to the commercial product 3W/mK level in 2W/mK, will also further improve the heat conduction performance.

Figure 8 reducing the cost of packaging components. Matsushita Electric Works to extend the life of the plastic substrate by improving the thermal radiation properties of the plastic substrate, as well as the resistance to heat and light. TDK-EPC varistor substrate without the use of Zener diodes, can protect the large output power of LED from electrostatic discharge damage.

At the same time, Japan Risho Kogyo company is recommended conversion by epoxy resin to silicon, thereby improving the LED package in plastic usage. The company said that when exposed to light, heat and other environments, the life of epoxy resin is only a few thousand hours, relatively short. At the same time, people pay more and more attention to provide tens of thousands of hours of ceramic materials, but the ceramic is often more expensive than plastic. According to the company revealed that the use of silicon, a new type of plastic substrate, only a small part of the cost of ceramic, but can provide the same service life. "The company expects to provide samples in the first half of 2010.

The Japanese TDK-EPC company has proposed a method to reduce the number of components in the LED package. A high output power LED typically contains a zener diode to protect the device from electrostatic charge damage during packaging. TDK-EPC recommends the use of Zinc Oxide (ZnO) varistor, rather than the usual use of alumina (Al2O3) sub substrate. Even without the use of Zener diodes, the varistor can still release the charge and can withstand up to 12kV electrostatic discharge. TDK-EPC is currently introducing new varistor substrate samples and plans to achieve commercialization by the end of 2010.

The plastic package to solve the problem of

KYOCERA chemical has developed a plastic that is said to reduce processing costs, can be used in LED packaging production applications, such as compression molding (Figure 9). The company did not disclose details of the material, said only a thermosetting plastic. In general, the use of silicone plastic in the LED package has poor bonding force and has a silver plated for reflection, which makes it not suitable for compression molding. In addition, the soft material often leads to deformation of the wire in the package, and the product usually has excessive permeability, easy to make silver deterioration.

Figure 9 reduction in packaging process costs KYOCERA chemical packaging materials can be used for batch manufacturing, such as compression molding. DISCO presents a method to make a thin sapphire substrate easier to handle. Canon machine is designed specifically for the design of LED crystal machine.

The newly developed plastic solves the problem. Silver plated with the force of several times the silicon plastic, hardness is 2 ~ 3 times. The permeability factor is less than 100. KYOCERA chemical said the company's production target price will be lower than the silica gel. Current customers are evaluating.