LED lighting converts electrical power into both light and heat. The thermal system must manage the heat that remains within the assembly so LEDs, drivers, circuit boards, seals, plastics, and surrounding components operate within conditions appropriate to their design.
Thermal Path
Heat Must Move Through Several Interfaces
Heat can travel from the LED package into the circuit board, through a mounting interface, into a housing or heat sink, and then into surrounding air or adjacent structure.
Each interface introduces its own material, geometry, contact quality, and thermal resistance.
Circuit Boards
Transfer Heat Away From the LED Package
Board construction, copper area, LED placement, spacing, interface material, and mechanical contact affect how heat leaves the LED region.
LED Circuit Boards →Housings & Heat Sinks
Use the Mechanical Structure to Spread Heat
Aluminum housings can serve both structural and thermal functions. Fins and increased surface area can help transfer heat from the housing to the surrounding environment.
Ambient Temperature
The Environment Is Part of the Thermal System
A fixture installed inside hot machinery or a sealed enclosure has different thermal conditions from the same assembly operating in open air.
Orientation, nearby equipment, airflow, process heat, and surrounding surfaces can all influence temperature.
Temperature Measurement
Validate With Relevant Sensor Locations
Thermal testing is most useful when measurement points correspond to components or interfaces that matter to the design.
Industrial temperature-measurement resources include thermocouples and RTD sensors used in many types of process and test systems.
Environmental Validation
Test Under Realistic Operating Conditions
Temperature should be evaluated under realistic electrical load, ambient temperature, orientation, enclosure state, airflow, and duty cycle.
Controlled test chambers are used broadly in industry for environmental testing where defined conditions are required.
Selection