Thermal Considerations for LED Components in an Automotive Lamp

Abstract

LED's in automotive lamp applications have been utilized effectively for functions with low light output requirements and for styling purposes. In recent years, high to ultra high power LED's are becoming a light source option for virtually every automotive lighting system. For exterior automotive lighting, these light sources have distinct advantages, but also unique thermal issues compared to conventional incandescent light sources. This study describes two methods of determining the junction temperature of an LED or array of LED's, direct and indirect. Both are based on temperature measurements, but the indirect method also requires a thermal resistance specified by the manufacturer. The direct method utilizes the intrinsic behavior of the junction voltage drop at low current (<0.1mA). A computer model for a typical plate finned heat sink design for a high power LED automotive lamp was experimentally calibrated. Design of experiment analysis was performed using a 3 level 3 input factor full factorial test matrix. The factors were defined as an active heat sink surface area, convection coefficient correlated to an airflow, and environment temperature. A quadratic model is generated from the results of the factors and significant interactions to the response.

A Comparative Modelling Study of New Robust Packaging Technology 1 mm2 VCSEL Packages and Their Mechanical Stress Properties

“…The dimensions of all packages were ensured to meet the manufacturing capabilities for semiconductor backend processes such as die-attached (DA), wire-bond (WB), lens-attached, and potting with requirements for measurement within a Six Sigma process specification. According to automotive specifications, the maximum temperature stain for the inner component as a dashboard component is only 200 • C [17]. Therefore, to ensure the robustness of the package, the measurement temperature ranges were chosen to be between −40 • C and 260 • C. The diffuser was developed on the top chip for the first time, rather than using the lens as a medium for a diffuser or separate component.…”

Metodologia de Projeto Eletrotérmico de Leds Aplicada ao Desenvolvimento de Sistemas de Iluminação

“…Em situações onde o gerenciamento térmico é um desafio, como em iluminação automotiva e lâmpadas compactas, o projeto do sistema pode ser complexo [1][2][3][4]. Além disso, a principal dificuldade encontrada para a popularização da tecnologia de estado sólido em iluminação tem sido os efeitos causados pela temperatura de operação [5].…”

Integrated Off-Line Ballast for High Brightness LEDs with Dimming Capability

“…At present, significant efforts are being performed in the development of lighting electronic systems, as one of the major research fields related to energy savings and sustainable development. Among other causes, this is due to the continuous improvement of High Brightness (HB) and Power LEDs as outstanding light sources [1][2][3][4][5][6][7][8]. In fact, these devices exhibit a continuous increase in its luminous efficiency and a high operating life and reliability.…”