Lamp with rigid LED strip - Design and thermal management
Investigations are connected with design and application of thermally and cost effective rigid LED strips. Standard FR 4 PCB is used for making rigid strip and LEDs are soldered on it. Special copper pins soldered underneath LEDs contribute to low thermal resistance between LEDs and heat sink - like when MCPCBs are used. Application of this type low cost rigid LED strips allows decreasing operations (and expenses) connected with assembling of LEDs onto a heat sink several times. A lamp for interior lighting is designed on the base of this type LED strips. Thermal management calculations are made and proper heat sink is chosen. Thermal loading of LEDs is experimentally tested at various ambient conditions (air temperatures from 20°C to 45°C) and different current values through LEDs - up to 600 mA. Infrared thermography is used for evaluation of temperature distribution on LEDs and heat sink. Thermal management investigations show very good qualities of developed LED strips.
LEDs' thermal management aided by infrared thermography
Investigation deals with LED's thermal management optimization in dependence of operating condition aided by application of infrared thermography. Thermal management calculations allow estimating temperature distribution on the LEDs, metal - core printed circuit boards (MCPCB) and heat sink but often real results may be different and experimental investigations are necessary. Good results are obtained using IR thermography with IR camera for the middle IR spectral region (8 – 13 µm). Application of infrared thermography allows obtaining temperature distribution at real operating conditions. Thermal images analyzing allow obtaining real temperature distribution on the LEDs, solder points and different areas on the heat sink at different operating conditions. Results of this investigation allow adjusting proper LEDs' regime of operation in lighting system with maximum light output in dependence of ambient temperature conditions and to ensure long life (over 50000 hours) of the LEDs.
Reflow soldering processes development using infrared thermography
Investigation deals with application of new kind of soldering equipment and development of reflow soldering processes for electronic devices using this equipment. It is based on low inert heaters for the middle IR spectral region. Due to low inertia of the heaters temperature changes in the soldering camera may be controlled precisely and the soldering cycle may be realized at the same place without conveyor belt. The printed circuit board (PCB) of the device is relatively big with different electronic components density in different zones of its surface. Used electronic components demand precise soldering cycle parameters realization. Temperature monitoring of the whole PCB's surface necessary for technological operation development practically is impossible by conventional measurement techniques. Good results are obtained using IR thermography with IR camera for the middle IR spectral region. Results of this investigation allow adjusting proper regime of operation of the soldering equipment and successful realization of soldering processes.