Thermal Management in High Brightness Light Emitting Diodes By Using Cu/Diamond/Si Composite
|關鍵字:||散熱管理;發光二極體;鑽石複合材料;熱導率;熱阻;theraml management;light emitting diodes;diamond composite;thermal conductivity;thermal resistance|
In this thesis, the main idea is to produce a direct heat dissipated channel by let artificial diamond particles directly contact with the chip side. The thesis includes two themes: first part, the artificial diamond particles were filled into the patterns on Si wafer,and electroplating Cu to fix the diamond. Then we transferred Sapphire substrate of LED to this high thermal conductivity Cu/diamond/Si composite substrate. The reason for this process is that diamond have better heat dissipation properties compared with the sapphire substrate. With better heat dissipation the transferred LED device could be operated in a much higher injection forward current and provide much higher output power. However, diamond is extremely hard and not conductive, so the Cu and Si aisle played an important role in electrical conduction. Si aisle also act as a cutting aisle for the LED transfer process. There are several issues including: pattern choice, how to fill artificial diamonds, wafer bonding, laser lift-off, and device fabrication. We change experimental conditions and processes for our desired device. The second theme is the producing of high distribution single artificial diamond layer on Si wafer, and selecting the appropriate bonding material as die-attach material. The experiment is divided into several part. Production of a high distribution single artificial diamond layer on star board, bonding with solder, BCB（Bzocyclobutene）and Cu. Structural thermal resistance measurement were analyzed and discussed. To sum up, we propose a new idea in electric packaging by using diamond which has high thermal conductivity to improve the ability of heat dissipation of die-attach material.