Modular Surface Mount LED Assemblies for Signal Lighting

Advancements in LED brightness have opened new applications in the field of exterior lighting. The properties of LEDs introduce new requirements in the areas of mounting and lamp-assembly design. Designs must take into account all interacting factors that can impact system performance, such as color, peak candela, off-axis light distributions and thermal management. In addition, designers want to contour the RCL (Rear Combination Light) around the corner in the X- as well as the Y-axis of the car to realize different 3-D shapes. The use of SMT High Flux LED is a new innovative submount technology that fulfills design freedom and ease of assembly into lamp housings. An additional advantage is low thermal resistance to drive the LED with the highest possible current allowing high optical efficiency. Furthermore, these solutions need to be very cost efficient. The advantages of this concept will be described in general, including production flow, as well as thermal and optical investigations. The mentioned solution based on so-called “submodules” that are sufficiently arranged can realize all wishes of the designer while fulfilling production and technical efforts. In addition, the production flow will be described. Afterwards, possible applications for RCL and CHMSL will be shown. Also mentioned is a new Super Flux SMT LED (used also for indirect lighting) driven with a current >300 mA and a Flux of about 25 to 40 lm. This is possible due to new technologies allowing low thermal resistance assembly methods. Examples will be given to show how this kind of module can help solve heatflow problems in this case.