| 摘要 |
<p>A solid state light apparatus ideally suited for use in traffic control signals having a glass-to-metal hermetically sealed LEDs. Current state of the art solid state signals utilize LED's with plastic/epoxy seals. A glass-to-metal hermetic seal is over 1000 times better at sealing LED's than a plastic/epoxy seal. Plastic/epoxy seals allow Oxygen and other contaminants to come in contact with the LED semiconductor material. The LED semiconductor's are composed of chemicals such as Aluminum (for example AlInGaP is one of the material used for red and yellow LED's), which over time and exposed to Oxygen, chemically changes the LED material from aluminum to Aluminum Oxide. Increased temperature accelerates the chemical changes, therefore keeping LED's cool and sealed greatly reduces permanent light output degradation. The chemical change of the LED semiconductor material is one of the primary causes of permanent light output degradation in LED's. The combination of a glass-to-metal hermetic seal in conjunction with a superior thermal design has an exponential effect on the MTBF of the LED array's light output.</p> |
